I don't think that necessarily true, a lot of people want to be anonymous just for the sake of not feeling that every move is recorded. Not cuz they do illegal stuff online.Yes. And how much distrust people have for those using true anonymous services such as Tor.
But, there is a large crowd that can't be arsed reading up on things and just think that they are anonymous as soon as they switch on their free VPN service not having a basic understanding of how it works.
Also, people seem to forget that it doesn't only impact speed and performance, it can also have an impact on the device battery performance. Sure, it won't slurp it like like crazy but you will most likely see the battery taking a slight hit when using VPN services.