It can be when done correctly, and when done between people whose body shapes are compatible. But it really depends on the people involved. Good scissoring doesn't look like what they do in porn. You need lubricant, to find the right angle, and it (most frequently) does not lead to orgasm on its own. It's kind of like a much more intimate form of grinding in that regard. Technically it's possibly to orgasm from grinding alone, but just like scissoring and tribbing, that's usually not the goal. It's highly intimate and fun with the right expectations. And it's only fun when both people are into it.