“I think many Jewish people refuse to make changes to help the environment because, (possibly subconsciously) we’re tuned to not worry about tomorrow because Moshiach is coming today.”
I think you probably don’t know all that many Jewish people. Jews do not use Moshiach or other Torah concepts as an excuse to act irresponsibly. And the arguments made here on both sides are grounded in logic although ultimately it is an empirical question – how much harm do plastic bags do and do the benefits outweigh the risks.
Either way please be careful about casting aspersions about mindless motives on an entire group of people – someone just might accuse you of bigotry.