Microsoft SSRS Cross Browsers

I'm on board with Microsoft as my main development platform, it's the direction I've taken.  The software is user friendly, there's a lot of info on the web for researching, you can get up to speed on new tech pretty fast, the community support is vast, the only thing I can't figure out is:

Why doesn't Microsoft play nice across all browsers? 

How is a Microsoft developer supposed to respond to users when asked why SSRS Reports and Share Point do not display properly in Firefox or Chrome?

I'm sure the roots go deep: Microsoft vs. Java; MS dos vs. PC dos; MS not compatible on Unix/Linux.

To assume that all users on the web will be using a version of Internet Explorer is kind of silly, so shouldn't a product intended to be distributed to as many users as possible be compatible with most of the browsers available?

I realize there are plug ins for Firefox that will allow users to render the reports as if they were viewing IE and some of the blame should be aimed at IE competitors.

I'm just saying...