This. I use scrounger on… I think three builds: Huntsman longbow (where it is actually quite fine since it relies on landing headshots to get your bonus crits going), on handguns I use with Merc (Merc has very high crits, realistically, you won’t land headshots on every shot, handgun kills SV with bodyshots anyway and can easily be geared towards killing all specials with bodyshots, so going for headshots is unnecessary overkill damage. You will eventually run out of ammo, but for keeping your ammo count high when shooting the occasional special or SV, it is more than enough to let you last until the next ammo crate) and on RV graker for the occasional buttstroke ammoregen.
On everything else, it is usually not worth it or simply a waste. WS has good ammo regen anyway and even with scrounger, you will eventually run out. You will melee often enough and you don’t rely on your ranged weapon. BH is more effective when going for Hunter and switching melee and ranged often. RV doesn’t have good crits and can only really benefit from it on graker. With extra ammo, ammo is not an issue on handgun. Crossbow is efficient enough with regular drops. Sienna laughs at the idea of ammo, anyhow.
Scrounger is not the source of this alleged issue, it would be simply a symptom. I don’t think moving it to melee would help, as it would prevent you from using something on your melee weapon that actually enhanced… well, your melee.
You could only tackle this supposed problem by dabbling with the ranged carreers. Admittedly, they backed themselves into a corner with those. You can’t take away their ammo regen without completely devaluing the entire carreer because most don’t have much to support their melee viability or survivability. I think debating about this issue has become kinda moot, since without massive changes to some very core design choices, we won’t see much alleviation on this. And while I am perfectly happy with how everything works now, by and large, and you could say I am rather biased and would advocate against such changes, I think if everyone’s being completely honest, the chances of such radical changes happening after such a long time are rather slim.