Anyone that has read my reviews of TNA or ROH knows I'm no fan of Daniels, mainly because his matches bore me to death as I hate the style he uses beyond belief. However, that's not something I see holding him back.
I'm not entirely sure why, but I think a lot of the problem boils down to he's never really won anything big. He's always been booked as the guy that is a step below the main event but never really does anything. Think back to the three way AJ/Joe/Daniels feud. Daniels never won anything in that feud and it was AJ vs. Joe with Daniels in the background.
Daniels has never held a world title, either in TNA or ROH. At this point it's almost expected that he won't. Not due to a lack of talent, but simply because he's not looked at as a guy that wins world titles, based on his track record.
Another thing I've always had issues with when it comes to him is his nickname. The Fallen Angel. What is that supposed to mean anyway? I know in the early days of ROH this was played up more, but in TNA it seems to just be a name more often than not. I know he's done a few religious/preacher related things, but more often than not he's just The Fallen Angel in name only.
Look at the nicknames of the two guys he's often associated with. We have the Phenomenal AJ Styles and the Samoan Submission Machine Samoa Joe. So we have Phenomenal, which makes you think he'll blow your mind, and a Submission Machine, which is self explanatory. Then you have the Fallen Angel. What does that make you think of? I've never gotten a clear idea of what they're going with for it. This is obviously not a huge deal but it's always been something that was off to me.
Overall, I think it's a combination of his track record and the fact that he's always been looked at as a sidekick. He's been on again/off again best friends with AJ Styles, the golden boy. It's like teaming with Hogan in the 80s. Randy Savage was awesome but he paled in comparison to Hogan as far as star power went and when he never won a big match over Hogan, it made him seem even weaker of a star, despite being arguably a far better worker. Similar thing here I think. You could also say he's the Christian to AJ's Edge.