Wrong. The deaths were impactful and gave weight to the story. It wasn't your typical Saturday morning good guys win bad guys lose tripe. There were consequences. The battle between Optimus Prime and Megatron was paced perfectly. You're a fucking moron if you think having the main protagonist and main antagonist, who also happen to be the two most popular characters, fucking die is anti-climactic.
I bet you're the type of dipshit who prefers the fast cut, shakey cam, 20 minute shitfest where protagonist A fights antagonist B for a bit, then we switch to supporting character C doing some bullshit with the computers in a race against time, then we switch to female protagonist X fighting female antagonist Y for a bit, then we switch back to the main fight between A and C, all of which are resolved nearly simultaneously with the good guys winning and the bad guys losing, typically with the good guys refusing to kill the bad guys once defeated, but the bad guys going for a last ditch dirty move when the good guys turn their backs, only for the good guys to respond with a lethal finishing move.