Because for PS3 games you were forced to split it with another user unless you wanted to pay $40 for both resells. On PS4 is different because there is only one resell. Why risk the account for only $5 when you can have it all by yourself and be 100% sure that nobody is going to steal you account. (I am not saying those persons who are buying the locked slots are scammers or anything)Never understood that argument, nobody had a problem when we had multiple resell spots. It's just the price disparity people don't like. I might change the pricing to fill a spot.
What will you choose?
Saving $5 and share the account with someone else or paying $5 more and having full control on the account.