That sentence in isolation was not MS's response. Let me break it down:
1) MS thinks same markup and standards compliance is imporant.
2) More than one dominant browser is necessary or you end up with defacto standards, which often leads to problems down the road (as we've seen). They reference a blog post that talks about this problem today with Webkit. And frankly the same problem existed with IE in the past. I recall the same issue with gcc on Unix platforms in the past too ("Is that legal C?", "I don't know, try it in gcc").
3) How do you get same markup and prove it, once you've established you need more than one browser? You probably need comprehensive tests and working with W3C is probably the best group to handle this. That is the reference to the sentence you made.
So you think Microsoft’s real answer which should be read into their statement is:
“Microsoft is using our own rendering engine out of a sense of duty to web browser diversity, because we don’t want the web to suffer the problems of monoculture.”
I'd phrase it slightly differently, if you want a one sentence response. Which is "Standards are important and we believe that multiple browsers and rendering engines are necessary for improved standards compliance across the board."
1) MS thinks same markup and standards compliance is imporant.
2) More than one dominant browser is necessary or you end up with defacto standards, which often leads to problems down the road (as we've seen). They reference a blog post that talks about this problem today with Webkit. And frankly the same problem existed with IE in the past. I recall the same issue with gcc on Unix platforms in the past too ("Is that legal C?", "I don't know, try it in gcc").
3) How do you get same markup and prove it, once you've established you need more than one browser? You probably need comprehensive tests and working with W3C is probably the best group to handle this. That is the reference to the sentence you made.