Your rant about IE is strange given that IE, a for a long time, was nonstandard. Think about it, you are asking developers to support a non-standard set of browsers to reach a "large" use base. How is that any different from the guys at mailbox supporting a non-standard API to reach a large user base?
The web looks fine in standard supporting browsers, and as of now that is Gecko and Webkit browsers (which by the way make up 99% of OSS browsers, like Midori and IceCat). Most of the other non-Gecko/Webkit browsers are Trident based, closed source, and only support Windows.
Using the web is a bad example for showing that there is a "proprietary mindset", when in fact all the standards about the web are completely open.
There's an important distinction that needs to be drawn here.
It's perfectly okay to say 'we support modern standards, older versions of IE don't comply with modern standards so if you use IE, you need to upgrade to a recent version'.
It's not okay to say 'you can't use even recent versions of IE because we don't like the brand name'.
(I think it is the former rather than the latter that people are generally doing, but it's worth clarifying the distinction.)
The web looks fine in standard supporting browsers, and as of now that is Gecko and Webkit browsers (which by the way make up 99% of OSS browsers, like Midori and IceCat). Most of the other non-Gecko/Webkit browsers are Trident based, closed source, and only support Windows.
Using the web is a bad example for showing that there is a "proprietary mindset", when in fact all the standards about the web are completely open.