Your point makes total sense, but I am telling you now that a lot of fans, especially original fans, like me, will never ever stop playing the old games and will probably still put the old games first.
OK, but it's just a nostalgic factor, because MK9 is without any doubt a better and more funny game than every other MK.
In all honesty, would you still play the sloppy (in a good sense) MK1 over MK9???
Total respect for it, I first saw and played it in 1992 in an obscure arcade and fall in love with it in 2 seconds, but all I want now is MK9, and if I play the older games, it's even worse, because I see the difference and definitely need to take the next step.
Cool if older games are included as a bonus/easter egg and whatever, but would be just that for me, a bonus thing which will bring back so many good memories but I don't feel like I want to play them again as of now.