No , it’s not allowed. That’s similar to some people making accounts to exploit the free 1 month Gamer Club that is available to new accounts. However, having 2 accounts is allowed but trying to exploit or cheat the system will get both suspended. Do note that having 2 accounts mean you have to verify both separately as well.
I can only think of some reasons that they would be doing it. But it is not allowed.
- Getting high good reviews to scam people.
- Getting high good reviews then commenting on his other account that his legit when his selling something very expensive (scam)
- Wants to spam listings on both accounts but need certain amount of ratings to do able to list many listings.