While I dont think Kylo gets enough credit for his abilities in TFA, I also dont think its fair to expect him to be some all-powerful badass either. Part of what I think makes him a great character is his insecurity about not being as powerful as his grandfather and it pisses him off. I think he'll definitely become far more powerful under Snoke's (sith?) training, but he doesn't need to be the dark side equivalent of Rey. There are so many people who are suder-duper strong with the force and have midichlorian counts of over 9000, I think its good that we are getting the joe-shmoes of the force.