Sorry, but you seem confused - using "Microsoft" and "Market economics" together.
Microsoft got where they are by making sure that market economics does not (or at least didn't) apply in the IT world. Don't forget that they have been found guilty several times of using illegal and unethical business practices to make sure that there was no viable alternative.
History is littered with the corpses of small businesses they forced out of business and stole technology from - the typical M.O. being to incorporate the competitors technology into Windows, and when the small company sues, they just drag it out until the small business runs out of cash, folds, and the problem goes away.
Alternatively, they deliberately make their own systems non-standard and keep moving the goalposts to prevent real competition - this is what the EU case was all about, their deliberate and calculated policy of making sure that nothing but a Microsoft server will work properly with a Microsoft client, and nothing but a Microsoft client will work properly with a Microsoft server.
Yes, businesses round the world SHOULD have seen what was coming, but they fell for the marketing and spin (and even in the early days, some good products) - I've worked for management that are so brainwashed that they really believed themselves when they said "people send me Excel spreadsheets, therefore I must have Excel". Many years ago I was, and I claim no originality for this, warning that allowing Microsoft to dictate what people use was the equivalent of simply writing them a series of blank cheques to fill out and cash whenever they feel like it.
Hopefully, the combination of the EU case making the protocols more accessible, and the backlash over Vista will dampen their dominance and we can slowly start to get back to a market where users can choose on the basis of cost and features instead of commercial blackmail.