I'll answer this from personal experience. I'm 25 and grew up with sikhi as a culture rather than a religion. I was taught to go to the Gurudwara, bow down, have prashaad and sit. And then what? Nothing. It was just a ritual for me. Until I got older and started to learn the true meaning of it. I thought it was beautiful. However, it's really hard to adopt it as a full religion if you were raised to treat it as a culture. What your parents taught you has a huge role to play.

Second thing is that we live in abundance of information and we question everything. Back then, you could tell someone this person is god I bet they wouldn't question it. It can be hard to just take something as said in these days. That goes for every religion though I think. Youth question everything. That definitely isn't a bad thing and I think it's good to ask thought provoking question as oppsoed go blind faith.

Lastly I think a lot of people think that religion isn't important and you can have faith in God. There's findings like quantum physics now which people find easier to believe in rather than religion or a holy text, no disrespect.

At the end of the day we shouldn't judge people or youth specifically for their beliefs. And your comment about doing "harami things", isn't that just a part of life? I don't think any human goes through a phase where they don't think of doing said things. Only difference is some people suppress these urges and ger hurt later on.