In general web developers seem to kowtow to the most to ridiculous compatibility requirements--how many still fret about IE6 and IE7 compatibility?
In no other industry do consumers get that kind of luxury. It'd be like the music industry putting new releases on cassette tapes for the people who haven't upgraded to CD or MP3 yet.
Tell that to the corporate IT people who manage thousands of workstations and support internal intranets that were designed around those older browsers.
They can very well keep ie6 for cruftmaster97(tm) but they could provide chrome or firefox to browse the 2012 internet. I know some people call their browser "the internets" but it is in fact just a regular application that you can install as many of as you like. Kinda like if you said we can't use Latex for our yearly report even though you could create all diagrams and tables directly out of the database because we already have a publishing software installed. Word.
Wait, that is exactly what IT would say.
In no other industry do consumers get that kind of luxury. It'd be like the music industry putting new releases on cassette tapes for the people who haven't upgraded to CD or MP3 yet.