I'm on record as believing that the over-saturation of Trek during the late nineties lead to it's downfall.
I'm worried that the same thing is happening again. Currently we have HD season one of ENT, HD season three of TNG and the Nu-Trek all vying for our money. I could afford to buy all these things but I do not have the time to watch them. I have a family, my time with them is precious, so I will choose to see the new movie this month (I am only halfway through season two of the HD TNG and ENT was never big on my list anyway). But I got thinking - I hope my (and other peoples) decision does not affect any possible future remaster of DS9. Why the big rush to get it all out anyway? They rushed season two TNG and look how that turned out. Surely we'd be happy with two releases a year, done well?
The same reason ANY product is put out: to make money.
Nothing more, nothing less.
And there's no "over-saturation". What's happening now (one movie every few years) is NOTHING like what went on in the 90's. In fact, quality of the productions aside, the 90's were a better time.