Probs cause they randomly buff/nerf stuff, so they keep them incase. Bungies own fault for having no idea what to do with the game changing systems constantly, so there's no easy way to get an exact item back once its dropped.

I would argue that you don't need any non-exotic scout rifles at all these days, or primaries in general.

I do have about 30 different shotguns that I never use though.

Exotics too, if it's not an Exotic you use often, you can make due with a collections roll. It's cheap to MW if you're at the point where you have multiple builds, and weapons are just weapons, if there's no high kill tracker, you don't need to worry about pulling (Hawkmoon, DMT, and the craftables non-withstanding).

Shit purples drop like candy too, so infusion fodder's not an issue.