"Stupid" is the only way to describe it. The plot is laughably incomplete
What's incomplete about it? The lack of resolution? What kind of story would you liked to have seen?
The soldiers drop Optimus off. That is all they do in this movie.
There's a subplot about the government having second thoughts about the autobots, but if you think about it, it's irrelevant. Nothing in the movie is affected by this subplot.
It gives them something to do in the plot, and raises the stakes of that element a bit, making it more than just another NEST outing. It shows the broader bond between the NEST team and their robot overlords.

. And it's conflict. It's one of the few conflicts found in the film, one of the few elements of Transformer/human interaction that is explored.
A fellow robot died in order to give Optimus his upgrade. Upon beating the Fallen, what does he do? Chucks it aside like so much waste. A fellow robot died to give Optimus his strength back.
1. Jetfire was more or less already dying. He seemed to know this.
2. As someone said, what's Prime going to do, transform into a semi with jet wings?
What i didnt like was the Starscream/Megatron dynamic, as i said in my review as well. Megatron was abusing SS all the time for no reason. In G1 Starscream often contradicts Megatron but Megatron is barely abset.
4) Starscream was a wuss. In G1 he had some guts and he often spoke his mind even though he contradicted Megs and without the latter beating him all the time. Megatron lived with Starscream's treachery. Here SS was constantly bowing and hoping that Megatron would spare him, while Megatron was overly abusive towards him.
It's from the comics. Megatron's constantly shooting Starscream, beating on him when he talks back, etc. Starscream spoke his mind a bit in the movie, didn't he?
22) Didnt like how Megatron was like Vader. Galvatron was Unicron's servant as well, but we saw him hate Unicron and bow with difficulty. Here Megatron is honestly loyal to the Fallen. It never crossed his mind to use him and then betray him and use his device.
I thought the film made it pretty clear that Megatron was loyal to the Fallen's ideas, because he wanted the machine to be used for Energon purposes. When Prime took The Fallen on, Megatron wasn't exactly helping. He fled with Starscream, and left his mentor/master to die.
Re: The Allspark and the Matrix reviving and killing...both in the comics have multiple uses and meanings. It's something of a MacGuffin. Always has been.