I haven't proofread yet, so I apologize again if I did any mistakes in my writing.
I think it's pretty normal that someone who is accostumed to playing with a lock-on based system is gonna have a hard time trying to deal with the lack of it, specially if it's so engraved in their mind. Likewise, someone who has never been fond of lock-on system is likely going to enjoy the lack of it. It doesn't necessarely mean one of them is bad, however. If anything, it says that both are actually good. A lot of people dealt with the lock on in past DMCs just fine without problem; right now, a lot of people also are able to play DmC in its entirety and have had no difficulty with the lack of lock-on. If either of the control systems made the game simply unplayable to anyone, no matter their prefferences or motor skills, then that'd make it objectively bad.
It doesn't mean one system is better than the other, just that some people are more inclined to one of them (although the possiblity of someone being able to deal with both is not excluded, of course). So all in all, I think the issue it at hand is a mixed matter of prefference and the playstyle one is used to play with and not really of skill.
As for myself? I'm not in favor of one over another. Lock on system, I admit, made it much easier to pull all of your moves and being able to focus on the enemy of priority, but I really disliked how it forced you to share the same button for both jumping and basic dodging. It only felt like real frustration in DMC1, but in DMC3 and 4 I really wished they hadn't kept it that way. I just couldn't get used to it (reason why Trickster was in still is my style of choice in 3, though I do enjoy switching styles from times). Of the many goods things I felt DMC2 brought (but implemented poorly) was a dodging button I wasn't fond that in DMC3 it was made to be limited to a style.
On DmC, I admit it wasn't too easy to get used to the lack of lock-on. In my case, though, what helped a lot was to approach the control system as a whole new thing. That is, settling my mindset from "I'll try to do everything I could in DMC4 and see if it works" to "I'll just mess with the controls and get a good feel of them before trying to master them". What the lack of lock-on benefits from is the ability to move around freely, unrestricted, and still have full acess to your moves and use them on the enemy of your choice. It also helps with switching targets inmediatly, no matter which direction or distance, if you're about to be attacked or if you want to keep crowd control. My only problem is the ocassions when I lose track of the enemy I am attacking and have to move around the camera to face it, but it's nothing that meddling with the camera settings couldn't help with.
Furthermore, even though both systems are perfectly fine in my eyes, they're only so in their respective games. That is, lock-on on DmC wouldn't feel very adequate and would be totally unecessary with the way the combat is fundamentally; meanwhile, no lock-on in DMC3 and 4 would be plain disastrous. Since the basics of both games differ (no denying that), what controls work for one do not for the other. And along with that, the issue of control preference comes into play as well: if you didn't like DmC's overall combat, you're also not going to be fond of its controls, regardless of how good they might be.
To conclude, however, action games like these would benefit greatly by a system that combines both lock-on and lack of it. Case in point: Bayonetta. It makes a wonderful job by letting you choose freely, at any moment, between focusing on a single target via lock-on and being able to change your attack's directions freely when releasing it. One may think it's pointless to have them both if all of your moveser is accessible, whether you're locking on or not, but I think the major benefit of having them both is that one may find some moves easier to pull off in lock-on, while others work better without it. More games you should follow this example and try to incorporate both ways into one control style, instead of chosing from one and base all of the gameplay around it.
