Honestly, on a technical note.... I don't think the MCU version of Thor is weak at all.
I believe that it's just a matter of "how" his powers have been presented on screen that have given the impression to some that he is "weak".
Likes others have said, when Thor fought against Iron Man and the Hulk, he was holding back. He didn't fight either of them with the intent to kill. The fact that he could rip off Iron Man's mask like tin foil (as shown when he has to remove Iron Man's mask in order to check up on his condition at the end of the New York City battle) but chose not to, clearly shows that he could really take out Iron Man if he really wanted to.
And in regards to Hulk, keep in mind that Thor's intent was to contain the damage that the Hulk was causing in his rampage. Thor had no intention in fighting Hulk in a battle to the death. The fact that Thor didn't even try to use any of his lightning attacks shows that as well.
Thor also took out two of those flying dragon creatures within the Avengers as well, and he was like the only one that wasn't placed in a position where he was getting the short end of the stick when going up against the Chitauri.
Everyone else were pushed to their breaking points where they were all being ganged up and nearly tied down. However, Thor was like the only one to hold onto his own still.
Honestly, it's just a matter of case where the people in charge of Thor, within the MCU, need to be more creative in both how they write and present his powers on screen.