The success rate can certainly be bad sometimes. However, you are missing the whole reason Aeria Games exists. It is a FOR PROFIT company. The way it makes money is by people spending money on AP. The "free" part of the game is really like a free trial offer. If you like the game enough, they hope you will spend money on AP. The game is not intended to be easy at all for players who don't spend.
Whether this practice is right or wrong is irrelevant. It's the way "free to play" games EVERYWHERE are run, and is standard practice. And really, why should Aeria change the game to make any part of it easier for free players? What does Aeria get out of the deal?
They don't even get "nothing", they get more free-loading players who won't spend money, but instead cost them money. That's right, each and every player that plays totally free costs Aeria some small amount of money. It costs money to run the servers, and the more traffic, the higher the cost.
Then there is another consideration. How fair would it be to ME if, after I got all my gear to +10 in the current play environment, Aeria suddenly made it easy for everyone to upgrade their gear? I know that I would be furious, probably enough to stop playing. CERTAINLY enough to stop spending on the game. So in making free players happy, Aeria would enrage the players who ARE supporting the game.