It's actually consistent with every other bit of evidence I've seen on evil paths. Light side / dark side jedi, the number of people who ran an evil party in BG, the sales numbers of Tyranny etc, etc. (and I get that the latter wasn't quite as evil as advertised but it was heavily marketed as a game for people who liked to play evil) Fans of evil playthroughs are a highly vocal minority. If you don't have an evil path in an RPG this will be mentioned in reviews and will become a hatesink for people love to hate on games.
In fact I suspect the numbers are actually inflated since Larian has been encouraging people to test it out. And it's the only way to see n00dz right now.
Granted, I get that people think this wasn't a fair test of the evil path so I would propose another: the hag fight could be changed so she can't be killed before offering her deal and Larian could report the numbers on how many players took the ability score boost and how many decided the end the hag's evil once and for all.