That's not exactly true- they are innovating, but they're also a patent troll. There's no reason why they can't be both.
There's nothing preventing a sufficiently large company from being some fraction X and another fraction Y.
All systems have bugs, which is why simpler systems are easier to manage in the long run.
If they wanted to crush Samsung, they'd insist that Samsung sell WP7 phones or nothing. If their patents hold up, that is their right.