If I’m not mistaken the $10 replacement is only the insert, not that there's anything wrong with that - I generally recommend reuse what you can!
If I understand the OP correctly, I think he/she replaced the whole wiper assembly with an aftermarket part and in the replacement process, had to bend the arm back to release the clip. The new wiper assembly, most likely aftermarket, does not work well but he/she thinks/questions if this is due to pulling on the arm to release the assembly. Generics are available all over but the aftermarket housing suck and does not distribute the right amount of force needed for our slightly -curvy at the top- rear windshield. I "think" it may help if you bend the two metal inserts/rails to give it more curve.