If the movie had explained that the new Republic was unwilling to form a standing army because the last time an army was formed during the Clone Wars that army turned against the Republic, I could have accepted the basic plot much more easily.

(I made up the above explanation.)

Then I would have understood why the Resistance was formed and why the new Republic was unable to defend itself.

However, without any exposition, the political situation in The Force Awakens is incomprehensible.

Furthermore, Kylo Ren should have defeated Rey in the lightsaber duel.

Rey should have only nearly escaped after sustaining serious injuries.

What is the purpose of training with Luke in the next episode if she is already superior to the antagonist?

Seriously, if J. J. Abrams had simply explained the political situation more clearly and had made Kylo Ren a more menacing villain, The Force Awakens would have been a much better film.

However, these two major flaws - an incomprehensible political situation and a weak villain - completely ruin the film for me.