So in other words miners make the ultimate decision? If this is the case, then Bitcoin Unlimited is even worse than I initially thought. Otherwise, elaborate what you mean exactly (since everyone can vote via software and miners create blocks).
I do not think that the miners having a lot of power in this decision making process is a bad thing, after all they are the only group that have a direct and lasting incentive mechanism acting upon them to do what is best for Bitcoin. Furthermore this would not just be up to the miners, they would still need to move with the economic majority, this is where the negotiation would take place.
So in other words, BU it is quite similar to BIP100 with the exception that with a combination of rogue nodes and miners the block size could be inflated so much that it would destroy Bitcoin? Don't deny this possibility with weird and not completely relevant to my statements.
I also do not see a better alternative then that since otherwise we would still be dependent on alternative implementations and their development teams in order to give us a range of choice. In that case however the power would still lie with the economic majority and the miners so it would not actually in effect be any different in that regard, it just turns what was a representative democracy into a more direct form of democracy in regards to the blocksize. BU is not even about increasing the blocksize, it is about giving everyone the freedom of choice.
This is your subjective opinion and is not based on facts. I'm assuming that you do not have extensive technical expertise (no, this is not ad hominem; more like a question).
After all the miners and the economic majority could decrease the blocksize under BU if they deem this to be necessary, BU just takes this power away from the development teams and returns it to where it belongs.
Return it? You are implying that it was like this before and that it was changed through time.
