I wouldn't be too surprised if part of the frustration is stemming from the fact that they learned about Uk'otoa super early in the campaign, all things considered. Warlock pacts work best (imo) if the patron is either a large, unknown presence for a long period of time or if they're an absolute constant nuisance. Keeping it in the middle just isn't all that entertaining or fun in the long term.Same. I really expected something more from Matt with Uk'otoa than generic underwater monster that immediately punishes their followers for veering away and questioning their monosyllabic orders.
It just feels like Uk'otoa's orders were meant to be something that was explored in the long term, with the group figuring out what exactly that meant when taking action meant do or die. Not don't do it, ignore it, and hope for the best.