See I dont like that anyone can do it. It makes the jedi seem much less special. Id prefer it to be people who were born with a sensitivity towards it and can use it in ways impossible for normal/average people.
I think they are born with it though and not everyone can do it no matter how bad they wanted to, and its because the movies made it very clear that some young children have the ability. They dont even like to train them when they are past childhood. So Im fine with how George established it, and thats set in stone because its in the prequels. Its an aspect of the prequels im totally fine with. Midichlorians never bothered me. Bad scripts did, but not some of the details about how the force works. I thought it was pretty cool actually since Im into science and all that.
It also plays into the idea that some individuals were sort of touched by a higher power when they were developing, making them unique for better or worse. This is why I dont think Finn is a force user, never will be, but Rey probably knew her whole life, has had various abilities, but never used them, or at least never made them clear to anyone around her. This explains why she is able to pick things up so quickly in TFA, because she kind of already knew how to do this stuff already. Maz says to her, "its always been there". She was even able to sense something about BB8 that kept her from selling him, and I think that was intuition from the force.