Precisely.
Having extra weapons simply gives one options. Just like having extra food, extra cash, extra fuel, etc. etc.
Personally I LIKE having options. I like having lots and lots of options.
Even if I decide NOT to use my 'spare' weapons to arm neighbors, I've got them to barter with, sell outright, or replace one of my primaries should it become damaged or destroyed.
There's really no downside to having a few extra low cost surplus firearms laying around IMO.
It's like having "too much" firewood or getting laid "too often". LOL.
Not to mention keeping a few here and there, off premises for a rainy day. Or night.