If I were a modder, I would address this problem (player X finds quest Y annoying but likes quest Z) by the game dynamically adapting to player quest preferences.
So if the player keeps finishing quest Z, its priority gets increased, or if the player fails to take up quest Y when available, its priority gets decreased.
I'm not sure if this is the best solution though, it's too much "let the AI take care of you" and less "you choose".
Maybe a better solution is for any quest giver to always offer multiple quests. And to develop quests that don't suck.
Maybe not based on the failing rate (because some players may try hard and keep failing ) but based on the refusal rate. Continuously refusing a type of quest would tag that specific quest as "undesired (or "anoying") and set it to very low frequency.
And yes it leads to your point about the necessity to add other quests...
BL current "issue" design does not allow multiple quest choice. It is purely RNG, based on frequency and specific conditions related to the environment / quest giver.
A great potential but it needs more pertinent conditions setting and 5 times more issues to make it feel less repetitive and more connected with the world...
The better solution is to delete "Lord needs horses" from the game completely. It is so bad, I can't even pick the words to describe.
"Hello, I need Aserai horses, but we are in Sturgia, so, here's ten days for you, and yeah, we need 253432 horses, because you're level 31, good luck".
Seriously, no other quest annoys and infuriates me as much as "Lord needs horses" does. It is very often and it sucks. I ignore it every time I see it.
The idea of the quest itself is not that bad, but defenitely not designed for mid-late game, when you are more helpful fighting the enemy than shopping.
One easy fix should be to limit the quest to a certain lvl of clan / party strength / player strength.
About the shopping quest in warband... I just remembered the most frustrating part.
Marshal was calling out for forming an army and the player, as a vassal, was requested to gather X troops and join the army within X days. It was always a pain in the a... to find the army and once you finally managed to join them, then you were asked to go buy some supplies...
Of course the time you were back (admitting you could find the army back) with the requested food, either the army got wiped out or marshal disbanded the army (or war ended)...
At least now in BL armies are easy to find...