1) UNIX isn't very good. I've used SCO UNIX, and it is very buggy. The MAC OS is a better comparison. Unless you know C++, and like to tinker with your OS constantly, use WIN 9X or WIN NT (at least, for the near future).
2) Gates has developed some really good software. This is good. He has also used monopolistic practices to force some really bad product on people. This is bad. There is a difference between free trade (IBM DOS) and monopoly (WIN 95 exclusively on a new computer, or you must buy the OS at some artificially inflated price). There is a difference in choosing my flavor of ice cream, and purchasing oxygen at $50 a bottle from the air monopoly (who is tasked, no doubt, with insuring the high level of quality the common man expects from his air).
3) This doesn't mean that Gates ought to be taken out and shot by the people's committee. It means (as, strangely, the reasonably effective judiciary of the U.S. is determining) that Microsoft, although allowed to make what profits it can from developing and marketing efficient software, will not be allowed to use the resulting profits and influence of that success coersively. This, simply, is what things like the Sherman Anti-Trust Act are all about.
4) If the parties concerned here would discuss their concerns in a reasonable manner, and not simply express their respective ideological lines, the discussion and resolution of these problems would be far shorter and much more coherent.