IME of reading many of these threads, the majority think that *every* passenger is entitled to put ONE bag in the overhead. If they checked one, then they can put their backpack above and have full use of the legroom. Ideally the FAs should encourage pax to put smaller bags on the smaller side bins (can’t recall how big they are on the 175/190s, but they’re pretty tiny on CRJs). But beyond that, first come first served.