What you are talking about is a change in societial attitudes. This ALWAYS takes a long time. What you may not realise is how much society attitudes have already changed. The idea of being out when I was a teenager was one that I can't even comprehend. People did it, but it's not something I was able to consider at the time. Now, however, there are sufficient number of teenage peers who do NOT mind having a friend who happens to be gay that it's something that can be considered.
It's not a steady progress. There are times where a lot of progress has been made, and then times when progress winds back. Overall, though, I'm seeing an improvement in society (at least Australian, New Zealand, European, Canadian and USA societies -- I apologise to any I've missed). There is still plenty of room for improvement, but we've made progress in a lot of areas and I'm happy to see that. But the core of that progress comes from within the society, and a key driving force is and always has been young people. This is why I'm an optimist -- I see more evidence of tolerance and respect in young people today (over all -- there are always exceptions) and they will be the core of the society for many years to come.