Yep Burner nailed it. The problem with wideband handlheld trancievers is that they are widebanded with small components that do not handle strong signals well. You use to hear it all the time on the ham repeaters. Somebody would have just went out and got a new widebanded HH and would be dismayed at the poor frontend on it. Now everybody just accepts it.
But my yaesu vx170 is pretty good though in spite of the poor scanning features.
I have an ICOM IC-208H mobile in one of my cars and I have a love / hate relationship with it. It's a radio that I absolutely love to
hate because of the poor front end in it. It has a sensitive receiver but it's as broad as a barn. It gets hammered a LOT in any urban environment. I actually have some scanners that have better front ends in them and work better in a dense signal environment than the 208H does.
I'm actually leaning more and more toward using the good (but expensive) commercial gear instead of acquiring more ham market gear. I've also been bitten by the APCO-25 digital and 900MHz bugs on Amateur Radio, so that means commercial gear only.
A real good test of receiver performance in a ham HT vs. scanner vs. commercial HT is when you try to listen to distant stations while hilltopping at commercial site. You'll be trying to listen while you've got cell phone site transmitters, a UHF TV station, a couple of FM broadcasters, one or more paging transmitters, and other VHF and UHF stuff operating nearby. In that environment, the commercial HT will likely win when it comes to receiver performance. A well known spot to test receiver performance is "Intermod Alley" in Chigago.
IIRC, the VX-170 is based on a commercial HT design. It's supposedly a commercial radio that's been Amateur-ized. That may explain why it performs well and is a great radio in spite of its poor scanning ability.