More realistically they’re going into a shop proposing changes immediately, getting slapped down, becoming disillusioned, leaving, and then trying again somewhere else. Even when people do make changes like this, it’s unlikely they stand the test of time, I’ve definitely seen people’s “pet changes” get rolled back within microseconds of them exiting.
You're absolutely right. "job hoppers" are often the very motivated people that are worth their weight in gold, but don't find a company that is on their level.
However as a manager you should probably not institute sweeping changes a "newbie" (he could actually be more of an expert than your own team, but you don't know this yet) suggests, but finding out why the newbie suggests them should be in your best interest. Often fresh eyes are the only ones that can see what is wrong. Dan Luu put this really well:
https://danluu.com/wat/.
A lot of catastrophe's could have been avoided (especially stuff that's morally questionable) if people listened more to the newbie who still isn't conforming enough to your team that he still sees what's wrong.
So my advice (to the managers): listen to the suggestions, and put your managerial clout and preexisting rapport with your team (which the newbie lacks) to implement the good ones, if there are good ones.
