It's a matter of opinion, just like some people prefer Craftsman tools over others, or Ford vehicles over others.
There are plenty of other brands that make quality golf equipment. Golf Digest does rate them in their yearly Hot List. They usually score very high, but only out-rate other brands in the "demand" category (which, coincidentally, they usually are runner-up to TaylorMade). They get criticized for lacking in overall innovation and not making products for mid-to-high handicap golfers.
Titleist takes on an elitist point of view, at least in my opinion. You can only get them from online places like The Golf Warehouse, or certified Titleist dealers (though they seem hard to find).
A lot of places, like D ick's or Sports Authority don't carry Titleist because it doesn't make sense, financially, to do so. Everyone knows that Titleist is geared towards low handicaps- and there aren't that many of those types in the world compared to the rest of my fellow Weekend Warriors. Why pay to have them, but not be able to move them out the door? Besides, other brands have just as good quality but use technology to help the "average" golfer.