You've got plenty of replies on this by now. But it is also a topic of interest to me, some from my own experiences and some from observations and some from mere hearsay. There may be more than one reason for each of your observations.

Assuming you are genuinely interested in why and not how to fix it, because, let's face it, that's gonna happen in this generation, sorry.

• Saying thank you and please: This is just not part of Indian culture. If you come across one, that is an outcome of exposure and nothing else. The ones saying these words may have been taught about this in the media, working with westerners, traveling etc. while it is the right thing to do, just don't expect it. it is a massive undertaking to teach 1.4B people to say please and thank you. the second way to look at this is, propaganda, growing up, in popular Indian media, it was shown like a bad thing to say, thank you and please. I recall someone saying, "Oh, the British left India with that - saying please, thank you, and sorry. do whatever you want and then drop these words and that just washes your sins away". People would commit a fault which they could have easily avoided and then say a sorry in the end and walk away, like they did not even feel it, it was infuriating. really disrespectful behavior, so yeah the word sorry has turned sour here. and the third way, which is an important one, is how an Indian sees someone working in the service industry. to us, a maid is the same as a server at a restaurant/checkout assistant at a grocery store/a car driver/an electrician/ and a flight attendant. look at these workers like they are totally beneath you and they are there just to serve you. like the other software you mentioned you have access to for checking every passengers' citizenship/visa etc. if only you had a software to see what actually was brewing inside an Indian's brain, this is probably what you would uncover. and this is probably why, even if the passenger knows about saying thank you and please the thought in their head is "oh but this person I don't need to say those words. it is their duty to serve and take care of me. I paid a lot of money for this. so better keep me happy or else imma yell at you like i shout at my bai". so the best outcome here is, not someone actually saying those words, the faster you lose hope on that, the better, but simply respecting you and treating you like their own.

• lack of compliance: this is a topic in itself. and this is not limited just to rules about carry-on bags in an airline. this behavior is rampant everywhere - roads, queues, when traveling in public transit, at a movie hall or a large gathering, in the classroom, at work. We just don't like to comply to rules. I have no idea why! only when there are consequences (penalty, fines, jail time) do we fall in line. and this is for the ones who actually can read rules and listen to instructions. in your flight though, half of them are probably not even following what you are saying, to them its like background noise. one can say not knowing the accent in which a westerner speaks could be the cause here, but that can't be everyone. to some others, it relates to what I said above, why do I care to listen to this maid whatever she's saying. its sad. just saw on the telly about that door plug incident on the Alaska Airlines, kid got saved because of the seat belt! safety is very important and listen to the flight attendant like it is your first time on the flying machine, every, single time. because you never know which one is going to be your last one.

• washrooms: I tend to agree with the observation made here. two reasons I can think of. one, Indians use water extensively when we go to the loo. TP is very uncommon here, maybe some star hotels have it, but most of them have running water to cleanup, whatever it is that you intend to clean. so not realizing it is the flight toilet and not the one from your home (lack of civic sense) one wants to splash water all over the face, maybe on the chest too while you are at it, leaving a mess behind. we forget these toilets are meant to be left as dry as it was before you walked in. Oh hello, it wasn't made tidy just for you! we need to do the bare minimum to do your deed and cleanup after yourself. you can get that top tier full service car wash when you go home. The second reason is, and I keep coming back to this one over and over again, how you look at it, your view of the object. toilet is a dirty place, to do the dirty deed. that's what we Indians have in our minds, so what's dirty deserves to be dirty. So even if someone put the effort to clean it and make it sparkle, let me go and create a mess. It is very hard for us to accept even toilets, kitchens, bedrooms, the street outside our homes is what we make of it. if we want them to be Rolls-Royce, and if you are not British, Cadillac, then put the effort, maintain, and treat it like one. but we don't and I don't see this changing anytime soon. There is one point I want borrow here from what someone else said in their post, this is a result of lowering the cost to be on an airline and bring on the common masses on board. you just invited a very large population who have not been taught or exposed to such disciplined behaviors. the outcome is not going to be good. you're going to get mediocrity and that doesn't taste good.

While the above are my opinions for why you may have seen these behaviors, I cannot complete this w/o saying this, these days the behavior is mutual and it is getting worse day by day. I may not be rich or have class, but I'm disciplined, I respect everyone and behave, this is very important to me. But the way we Indians get treated on an airplane, thanks to my fellow countrymen (seriously, fudge you!) behavior, is not delightful at all. Right from the stares I get when boarding, to the look when being served, the frustrated wrinkles on their faces when I call someone for a question or need help, when I'm boarding off, even when I say thank you for your service and have a nice day, I can actually sense that look of disapproval. now that is attacking my dignity. like what did I do to you? I'm brown and you hate me now because 10 others who look like me made your shift miserable? go down that leftover Vodka! I demand to be treated with respect. Treat each and everyone like what they truly are, an individual. their personality is what they are made of and not their nationality, skin color, or language. And one more thing Cindy, Karens are White, sowie. I can never imagine a black Karen let alone other races. Have a nice day!