"compatibility updates whenever you upgrade your software"
While that never happened with any major MT upgrade.
Never. Ever.
I guess we've all forgotten how many blogs in the past have stayed on older versions of MT because they relied on some plugins whose authors didn't update for newer MT?
This point is so moot.
With a flourishing plugin ecosystem, it's no surprise to see some minor plugins fail to have a new version to work on new WP on the release date. Most major plugins however, have authors or communities of authors who keep up with changes in WP in order to support newer versions quickly.
As for static vs dynamic, it's so deliciously ironic to recall how Six Apart announced to great fanfare that MT was finally able to do dynamic rendering, some years ago, only to see you trash the very feature today; on movabletype.com itself, no less.
This post is the kind of flamebait that I expect on any blog but a company's corporate one. I am disappointed, I'm sure Six Apart can do better rhetoric than that.