Contrary to what many posters of this board think, Hackmaster has quite a large following of gamers who find its ruleset prefereable to the radical alterations of 3E. A lot of it comes down to deviation from the source material. My prevailing philosophy is that anything that helps the game, while still keeping its most essential elements, is good for the game as a whole.
However, there is a strong contingent (judging from Hackmaster sales estimates I saw, anywhere from 35,000 on up) of players who feel that, while changes can be a good thing, the changes to 3E went waaay too far. It's kind of like changing the engine, bumpers, cab, trunk hood, transmission, and dashboard and seats out on a car, and still calling it the same car. Each change by itself is small; but taken together, it's no longer the same car, but a NEW car.
Then you have the fans of Hackmaster (such as myself and Col Hardisson) who enjoy it for the fun, and partly for the nostalgia. I myself accept the changes in 3E, and my players are all fans of d20 who most of whom say they will never, ever, ever, ever, ever go back to 1st or 2nd edition, for the same reason they will never wash clothes using lye soap and a river rock. I could do either, but prefer 3E. But 3E being the new lingua franca of gamers everywhere is not necessarily accepted by all - and you don't have to be a luddite not to accept it.