The fact is, after releasing IE6 around the year 2000, MS dissolved the IE team. Only around 2006 a new team was formed to create IE7 (which wasn't much better).

Conspiracy mixed with facts is... At the end of the nineties, Netscape was pushing to make the browser the platform, instead of the desktop. MS was quite worried about that, they had a monopoly on the desktop and used that to create a monopoly with their browser, so Netscape had no chance to do what they wanted. MS succeeded, as in delayed the process, it took maybe 15 years, after the death of Netscape and the rise of Google, to have Google and others make a platform out of the browser. Having the web stagnate and locked in to a browser like IE6 was for MS a desirable situation.