I think the better title for this thread would be if MK9 combos were better and easier to execute. That answer would be yes. The timing and feel of the MK9 combo system was more solid and more consistent.
I mean if you like fluid combos you would like MKX, if you like more distinct movements like dash cancels you'd like MK9. MK9 combos differ the most from other FGs so that could play a part in it.
I like MKX combos more personally but there are no right answers. That being said whoever said MK9 is better than MKX is on some good drugs because MKX is obviously a better made game in almost every way(I say that as someone who doesn't even like MKX lol).