Actually they are very up to speed on it. Up to speed on the fact that for reasons of security it is best for you to get it from the source, if and when you need it. Because not everyone does. I still haven't had a need to install Flash Player or a Java Runtime on my computer since I bought it last fall, for example.
This issue isn't Apple but rather websites that don't bother with the curtesy of putting in a link to the download page with the alert that you need to have the software.
Find your Flash version and make sure it's the latest version available. Never install or update Flash from a pop-up on a website. Always go to Adobe's site to get Flash or updates.
Try using the YouTube HTML5 Video Player to watch YouTube videos, when available. (May impact fullscreen viewing. See link for details.) Some have reported better performance with HTML5, while some have reported worse. Try it and find out what works best for you.