@alextheboss: Fallen's TK is definitely stronger than Wanda's, but I don't remember him attempting to use it on Optimus at all?
Either plot reasons or Optimus could resist if he's not caught off guard. It's sort of a thing in fiction a bad guy can blow away things with his mind to make them seem intimadating powerful and it takes a strong hero to beat them. Fallen actually could tk Optimus in the cartoons.
In the 200x He Man cartoons, Hordak could kill pepole with a thought yet King Grayskull was able to resist his tk when he tried to get close to Hordak.
There's also the fight between All Might and All for One where A4O was blowing All Might away at the start of the fight but not later into the battle. Maye he forogot about the ability. Some speculate A4O just chose not to cause he wanted to get caught. Although I doubt either of those reasons apply here.