By far the biggest problem in MMA IMHO is that the UFC just isn't as good at drawing in a variety of talent as all the orgs it bought out of drove out of business.
Pride, Rings, FEG, Inoki and even to some degree SF all took more risks than the UFC does IMHO, they went out and signed up guys very early in their MMA careers or even directly from other sports. The UFC does offer excellent money to the top guys BUT it takes many years to fighters to reach that level. Your talkings years in smaller orgs then a few more years building your name in the UFC IF you make it to the top.
The UFC's current tactics draw in American wrestlers pretty well and lower end BJJ/MT fighters but they don't draw in the quality Kickboxers, Judoka and even BJJ fighters that we used to see coming into the sport. Unlike US wrestlers these guys can earn serious money in their own sport either as pro's or though state funding/sponsorship, why would they take a risk moving to MMA when it might not come off and will take years to pay well even if it does.
You can talk about image but Crocop was Crocop because he was kicking guys heads off, Chuck was Chuck because he KOed guys with insane looping punches, the image behind that just added a bit of spice.
The worrying thing is that we've not seen the worst of it yet, todays MMA still has a lot of holdover stars from the pre Zuffa monopoly but as is increasingly being noted many of these are aging fast and in another 2-3 years a lot of them will be done as top level fighters.