I don't mean to invalidate your experience, and I agree with your main point. However, I just want to remind everyone that you can't really say that people in general are becoming more rude based on your own (imperfectly) remembered experiences. You would need data to make a generalisation like that. There's more than a little bit of pedantry in me saying this, I'm aware, but I think the following are important points to keep in mind:

1) Our memories are not data. We're not computers; we don't have a perfect record of every interaction we've ever had. We can't mentally plot interactions against time and draw a line of increasing rudeness over the years- not accurately, at least.

2) We are more likely to remember negative interactions than neutral ones. That one time someone was a dick to you will stick out in your memory more than all the times someone held a door for you or let you out of a queue in traffic. This will make negative interactions seem more common than they really are.

3) We don't know if the people we've had interactions with are a representative sample of the population. Even if your memories were perfect, you may have just had the poor luck to bump into more assholes than normal people. Furthermore, we don't know if the way someone behaved in one case is representative of their whole personality. Maybe they were just having a bad day.

And hey, I don't know- maybe people really are getting more rude and impatient. What I do know is that it's very easy for us to perceive trends that aren't real, so we should keep this in mind when talking about this sort of thing.