Why would we use bait and switch tactics to make money for someone we barely know, and do not receive payment from.
Era pc can have gun trading because they don't have gralat packs, there are less people and their server is mature enough to cope with scammers.
Think of how many accounts get "hacked" (given access because they are 'friends' and want to try their gun) and how player continue to give others access no matter how many times we tell them. If there was the ability to trade guns, all these taken accounts would be trading them away to themselves, hoarding guns and using them to ruin the economy.
Guns would no longer have any value, and people would ask ridiculous things for auction guns.