First, I agree with your assessment of the 2014 Vhuman. I think it's fantastic. What I wonder at, though, is why D&D Beyond's pie chart shows humans at 11.8% and Vhuman at 11%. You'd think that people would select the top tier version more often than the normal one.
+1 to all stats sounds attractive. It's +6 when the others get +3. Of course, with your system mastery, you know this to be false, but it's a very common "first read impression". Plus, it can be true if one rolls a lot of odd scores. Add, on top of that, the players who don't feel like roleplaying a non-human because credibly playing an alien mind is very hard and taxing, so they need some human, and their DM might ban vuman altogether.