Last thing we want to do is provoke an attacker and offer them challenges or puzzles indirectly to give them a flag to stay and continue to hack rather than move on to other hosts. If possible, I do not wish to let the attackers know that my iptables rules have TARPIT enabled for certain ports.
If I do not know that TARPIT is enabled, in most cases, as a user, it just feels sluggish or unresponsive and after a while, I'd imagine I'd just give up because the server is probably running slow or has a very slow hardware. I think last time I've tried to nmap on my TARPIT enabled host, it just reported that port was open, but did not slow it down, so from the attacker's point of view, it's business as usual.
Although it is more for the sake of concerns, from academic point of view, I am also curious to know if the endpoint has TARPIT enabled or not, and what one can do to make it less obvious.