If they put it in the ToS that it's against the rules for real world monetary transactions to happen, then it's their own fault, and they can't complain to the devs about it.
Well, you see, the transaction itself is only part of it. Selling accounts has it's own complications, and this is from the notion
you shouldn't give it away/share with anybody else. It is the account
you created, with
your pirates, and all the work
you put forth. Let's consider two different scenarios here to illustrate this central point.
Scenario A
User 1 sells their account on eBay. User 2 purchases said account, and is given access to it via the seller. A few weeks after the transaction, User 1 regrets selling their account, and decides to take it back. Due to the fact both sides will dispute account access, it is undoubtedly going to drag in TLOPO staff. So, who wins out?
User 1.
Players cannot change emails themselves, and therefore must contact staff to have it performed for them. User 1 gave
account access to User 2, but did not have emails switched, and therefore holds power over resetting passwords and communicating with support
as the account holder (i.e. the email tied to the account). However, this does not mean they will get off scot-free.
They may regain control over the account, but will likely face a ban due to the fact they sold it. So, in essence, both sides lose. Even if emails were switched, and User 2 managed to claim control instead of User 1, the end result would remain the same (banned due to ToS violation).
Scenario B
User 1 is friends with User 2, and both share User 1's account/pirates. A few months later, both friends end up getting into an argument, and User 2 ends up deleting User 1's pirates out of anger. At the same time, User 1 changes the account password - locking out User 2. As a consequence for allowing others into their account, User 1 has lost the progress they made.
Scenario C
Similarly to Scenario B, User 1 and 2 share User 1's account/pirates. During a standard play session, User 2 ends up saying a slew of foul language on User 1's primary pirate. Due to the extensive rule breaking, TLOPO ends up issuing disciplinary actions against the account. User 1 protests and states they weren't the ones who said anything wrong. However, due to the fact it was still
their account, they become liable.
In conclusion, all three scenarios illustrate why these provisions exist. Real-world transactions for trading would only make things more complicated for staff, and it would be even harder to solve due to the logistics of solving such disputes in the first place.