While its interesting to get different perspectives from around the globe, I'm not sure we'll agree on the principal tasks of government, so I'll leave that subject and return to the computer side of things.
Without trying to defend MS, it can only dominate markets that customers allow it to dominate. Nobody is forced to purchase MS products. They do so because, for whatever reason, they perceive that MS serves their needs. One of those needs is file compatibility with others, which by its nature, allows MS sales to feed on themselves. The more people buy MS products, the more people need to buy MS products to communicate with all the others who went before.
Perhaps it's also a function of job security for IT managers. Back in the '80s, the saying was that, "nobody ever got fired for buying IBM products." My guess is that, today, you can replace "IBM" in that phrase with "Microsoft."
Virgil