Yes, I think Microsoft is showing up with this move that their engineers are very lazy, expecting web developers to specify what IE must do when confronted with their page. This could be OK if IE was the only browser around, but this is not the case.
Besides, I find ironic that after the web started to move towards standard compliant websites, and IE stayed behind, thus forcing web developers to code workarounds for IE (and hurting other browsers in the process) or even dumbing down their sites with quite simplified layouts, now Microsoft expect them to do the same, but for compliance! It's ridiculous, there's a single standard, but Microsoft wants people to follow their tune, while other browsers had been implementing workarounds for IE (the defacto HTML standard) shortcomings during years.
I hope that after all the backslash, Microsoft sees this is not the right path, and either does the same as the competing browsers, or calls all the companies involved in the W3C to come up with a sensible solution.
Something that worries me is that, if they decide to continue this nonsense, and even if most web developers ignore them, they'll try to impose this "solution" by force, like making the future versions of Expression Web write this metatag by default to HTML files.