MMA fighters have style. If you don't know about fighting you should not try and point out styles. Off my head, MMA fighters tend to practice Jui-Jutsu, specifically brazilian Jui-Jutsu. They tend to practice kickboxing and Muy Thai for strikes, as well as kempo and karate. YOu have some with greco roman wrestling background there as well. MMA fighters have black belts and purple belts in many cases, especially the old scholers. Hell, there are guys who incorperated snapkicks for Teakwando with great effect. MMA is a way a very pure combat setting, you have to build not a single form, but a whole array of tools to be able to handle what you face. There is a Icelandic fighter who's strikes are almost pure Karate, and he fucking floored people with it. And that kind of pure style is rare in that it's not realistic to defend yourself with. Because if you only know a pattern, your shit out luck when the perimiters break and you stand in front of something you cannot control. There are Thai-boxers who fight grappling experts and who compliment their innate striking with footwork from greco-roman for take down defence.
TO say MMA fighters have no style is ignorant towards the sport and its athletes. These are accomplished fighters who when on top of their style, tend to be adept and not one but several styles. Not a single fighter steps into the squared circle or the octagon without a background in martial arts.
To quote Jet Lee on the subject of MMA fighters after having him beat some in one of his movies. "In real life, I'd been killed by one of these guys."