> So its not inexperienced engineers wanting newest hotness because they have no idea how to solve stuff with the tools they have, its sometimes senior engineers trying to justify their salary, "seniority" by buying into complexity as they try to make themselves irreplaceable.

The grass is always greener where you water it. They joined your company because the grass was greener there than anywhere else they could get an offer at. They want to keep it that way or make it even greener. Assuming that someone is doing something to become 'irreplaceable' is probably not healthy.

They want to make it "greener" for whom? I think that is the question.

I really don't understand this comment.