We could very well have a split user community within a few years. And the basis for all this is in-browser scripting.
I keep saying it and I keep seeing more evidence to support my case.
Don’t use any in-browser scripting. Then your pages work for everyone. Good old HTML and CSS 2.1. (CSS 3 too, sure, but it’ll take about 3 years after the first working draft is released).
Or you simply decide that you don’t need to support all user bases. That you’re quite accepting of developing a website only usable through IE7. That’s a very real, very valid choice to make. No different than the choices billion dollar companies make when they release a game title exclusive to one gaming platform. And these companies are successful at it too (otherwise they wouldn’t be billion dollar companies to begin with).
I have to accept that alternative.
However my personal feeling is that we should be striving for compatibility and usability. That our job, as web developers, is to make access to information as easy as possible. We should open the doors to information, not close them. Some will claim that a given script or platform is required because there is no alternative to deliver their specific type of information.
In very specific cases this might be true.
But I’d say 90% of the time it’s lazyness or other hidden agenda that drive development in this proprietary direction (like Microsoft trying to force people to use their products).
If you let yourself be overcome then web development will become a confused and sticky place to be in 3-5 years from now.
But if you free yourself of these added burdens (javscript, flash, silverlight, java, ajax, webos, etc.) and stick to what works for everyone (html+css) you’ll be well off.