This is nothing new. The bow/crossbow specialist had always the advantage of using less and easier to get ammunition when scavenging POIs. His disadvantage was that the stealth multiplier on headshots doesn't apply on horde night. It is diversification, if all builds were alike, why would you replay the game with a different class?
Usually you should have much more (bullet-type) ammo left on horde nights than a non-stealthy guy. This means that each shot with guns does less damage on horde night but you can use that ammo with utter recklessness to balance that out.
There was a long discussion about this about 2 weeks ago (with people on both sides of the stealth/bows too good - too bad fence), and the gist of TFP's response to that discussion was "Working as intended"
I'm all for more routes through a POI, but I have problems picturing what a stealth route should have different as a rush route. It isn't the case that people wiith loud weapons want masses of zombies, they want to save ammo and get to the good loot like everyone else. If you present two paths, one filled with zombies, one nearly empty, probably everyone would take the latter path.