Time Traveling Movies Are Dumb.

Well i got to thinking this new movie with Bruce Willis and Joseph Gordon Levitt(cha right he's a younger bruce).
Levitt is a hitman that mob hires -from the future or some shit- Sounds overly convoluted really.
So here is my question why do you need to send your marks back in time waste money and resources to kill people from your time?

It seems if you have the money and time to make a time machine ....you don't need to do this overly long winded way of killing people.....it seems you have a lot of power and money to just rule the world in your time if not !
then you have fricken time machine?! use it to be the owners of the said world in your time....
I may be thinking too much but......this movie's premiss seems stupid
And this is why i hate time traveling movies
Its like the character from heroes.
His name was Hiiro he could time travel it might escaped the writers...that oh yea time traveling is op....and he can just fix the or bring back character we want gone. All i am saying is......can we stop trying to make these movies ..it never seems we can handle it story wise since time traveling can always be undone by the fact you can time travel -_-