I don't have an opinion either way but on paper he has beat BJ, Randy, Franklin, Sokoudjou "who as someone at one point", Rashad, Shogun, Ortiz barely, Thiago Silva, and worth mentioning Bonner...
Not to mention some people think he beat Rampage. I think he lost that fight and to BJ which he fought at a Heavyweight, 225.
So he HAS fought in a different weight class and beat a lot of top guys. Not to mention he was undefeated until he fought Shogun, a "legend" Does it make him a HOF'er now? No? But I certainly think to some people he will go down as a legend because he has a pretty nice resume.
Not really a fan btw just stating facts...
Problem is most of the big names he has beaten were smaller then him(Penn and Franklin). Sokoudjou was never really any good. Couture was past his prime and he didn't really beat Shogun. He did a good job beating Rashad and Silva and had a very good fight with Rampage but that is about it. You can't give a guy legend status just because he was top 5 and beat a couple good fighters, they have to do a lot more then that or else we would have legends everywhere.
Machida is a good karate based fighter, nothing more nothing less.