i see your point, and im not excitied about it because i think its a novel concept, but the same could be said about almost everything in this world, movies, music, food, even design!
rarely is there anything anyone on this board comes up with that is a COMPLETELY new concept or idea, but we dont come out of the woodwork bashing it, (well maybe some of us do 
)
point being, yes i love movies of that genre, so when another one comes out and is kind of just a rehash of the aliens vs us or giant monster vs us concept im happy because i enjoy it and it never gets old to me.
I think most people feel that way about genres but yet feel the need to try and flex their “Film” knowledge by stating that the plot is not new or the acting is not award worthy, etc.
Not gonna say that people cant voice their opinion, but i just think its a moot point, and generally no one disagrees with what you are stating, they just dont care.