One reason MS may not go after the "violations" is that they are afraid of losing. Many patents have been granted, as the writer pointed out, for self evident things. (One wag once submitted an application for the ice cube.)
In many ways MS is like the old line book publishers fighting to keep their old business model.
Patents do serve a valid purpose, they were never designed to stop development or keep innovation from the market. Yet, that is exactly what has happened in software patents. I understand Intel getting a process patent on a way to manufacture a new chip. I do not understand someone getting a patent on putting an auction online. (I wrote an auction program in dBase II under CP/M back in 1982 for a dial-in 300 baud modem. Wonder if I can challenge the patent?)