A full splice sneaky pete from a quality builder gives the player a cue that will play great without the worry of getting it damaged, etc. A lot of really strong players like sneakies simply because they play great. A quality sneaky pete from a good cuemaker can be purchased for $350-600, which is a small fraction of what a fancy custom would cost.
For many players, it is also about not displaying too much "flash" at the table. It used to be that the sneaky was a tool to be used by the road players so people would not know they were good players. With the internet, it is not so much the case now.
Joe