MS has allways had a hard time competing with compnies that knew their market and delivered. MS killed netscape because netscape put out crappy software, not because of MS making a better product (even if it was free). So if the company MS is after doesn't screw up on its own MS will just buy them out.
Commodores problem was they didn't spend money on R&D and they didn't spend money on advertising. Their products were great when they first came out, but ended up being old news a decade later when other companies seen the new trend and started going that way.
The thing I like about microsoft is that they keep trying to either update their products to buy out other companies with the tech they need if they cannot do it themselves. They have a vision (sometimes later then others) on where they want to go and spend/buy to get them there. Commodore had no vision outside of the initial Amiga design (which they just purchased so Atari would not get it), and didn't bother to expand that product either on their own with R&D or by buying newer technology when they had the cash to do so. One trick pony that was bound to fail no matter what. Seems like Commodore was one of the first pump and dump companies to milk a product into the ground taking the money and running.