You can press P,P,P,K,P too fast and the combo doesn't activate. Does that in training, does that in combat.
That sounds more like you're just not doing your inputs correctly. The game, to many ends, resembles a Vs. fighter, when it comes to how it will not register your inputs if you do them too slow, or too fast.
Once you get the correct muscle memory down though, you're good. But again, it requires training, and a sizable investment of your time, assuming you want to see just how far the rabbit hole goes in this area.
Developers don't seem to get that the only people that care about Ranking, Difficulty, and Combos are a very niche group of nerds with nothing better to do. The larger group really doesn't care, want a powerful and competent main hero without feeling like you've SNOBBED US LIKE WE'RE SOMEHOW INFERIOR FOR PREFERRING SOMEONE WITH SOME ACTUAL POWER, and enjoy the settings and story since the devs hide secret missions and areas and spend a lot of time making you watch cutscenes and travel.
Again, don't see really what's the problem. Bayonetta has PLENTY of power, even without the additional stuff I speak of. The additional stuff just makes you better. You just need to learn how to properly hone it all. For all the options that the game gives you, there's plenty of stuff that's available for those who "just want to make it to the end", as well as those who are willing to explore the engine further.
Just because Bayonetta doesn't do more to hand it to you on a silver platter, like say, how it was done with Nero in DMC4, or the entirety that describes a certain other franchise, doesn't mean it's not there.
And you still really can't dodge while you're trying to input these long combos, and if an enemy decides to go nuts on you while you're putting it in and it's wanting a certain timing, well you're just SOL.
Actually, again, yes you can. When you start a combo, and then go into a dodge, the combo you started is "stored" (for lack of a better term), and can then be resumed after you finished the dodge animation (or cancelled out of it). This "Roll Cancel" is really how you can start doing some nice damage, dodge to avoid an enemy's attack (Activating Witch Time in the process, if you're good), and then continue the combo.
But the basic thing that can be stressed? This game REQUIRES you to learn the importance of dodging, not unlike Viewtiful Joe and God Hand before it. You have to learn what your enemy capable of, and how to best dodge it, if not counter it out right. In short, yes, home slice, you need to actually LEARN this game, in order to get good at it. The game makes for a lot of ways in order to help you along, but it's still on you the user, to get the most out of it.
Brutal Legend had longer combos, but they weren't necessary. In addition, it had an all-range, damage stopping Guard. This made you focus on knowing when to pull off combos instead of going in headlong. And in the meantime, you had plenty of shorter inputs that, though not as powerful, had effect. Stop an enemy in its tracks, daze them, set them on fire, etc. Brutal Legend would have been the best Action game if it had some more of the genre's traditional elements (like a freakin' lifebar) and the RTS hadn't gotten in the way.
And in some ways, Bayo is the same way. For the most part, you don't go in head first in Bayonetta, you wait for the right opportunity to severely mess them up. Also, there are a good number of combos that exist that are shorter, but no less useful and advantageous.
One good example? A nice BnB such a "PKP". It's short, sweet, and the third hit summons a forward hitting Wicked Weave Punch that will knock enemies away from you, which could give you some nice elbow room. Then by the time you get the special attacks such as Tetsuzanko, you'll get a nice "Hip Check" maneuver that's pretty much guaranteed to knock all but the toughest opposition back, plus can summon a Wicked Weave punch if you have 3 stocks worth of magic to spare.
Again, the basic thing is that the game has plenty in the way of depth and options, to help many different playstyles and users out. It's not unlike how most competent Vs. Fighters do it, like Street Fighter and etc. And like with SF, you really do have to know what you're doing, and what options are present to you, in order to get the most out of it and really "bring the potential out". That's pretty much all that can be said here.
If it's not for you...then that's nothing more than can be said here either. But there's nothing wrong with the game itself, either.