Eh, even the old school monitors occasionally had some early mortality. Figure the one you ended up with was already quite well tested by the time you got hold of it.
That said, the newer stuff is generally not well tested (if it's tested at all!) prior to leaving the factory. In the old days, a burn-in test of several hours was pretty common, while these days you're lucky if they bother to even turn it on before boxing it up and shipping it out. Combine that with the fact that the modern designs are a fair bit more complicated (for various reasons, some good, some kinda worthless), and it's not surprising that this sort of thing happens from time to time.
Figure that monitor would have cost you another hundred bucks or so if it was build on modern processes but to the same standard of quality that things back in the early 90s were held to. It turns out these days that it's cheaper to just replace things under warranty (or stick it to the customer, sadly) than actually test things prior to shipping them. If you attempt otherwise, the customers will just all go to whoever's cheaper, and you'll be out of business pretty quickly.
Of course, I'd not heard many good things about the Makvisions. I think they only reason people are buying them is that they're the only option left for new production.