The Crimson Binome
Hero
I sympathize with your players, because I also hate trickster fey. I think they're silly, and that they detract from any setting where they exist. It's not a matter of fear or respect, though. The issue is that they don't make logical sense.How can I make the fey into something they'd actually respect? Either as adversaries or as allies.
If you ask a wizard how they cast spells, then they can give you complex theories about natural laws and interactions between elemental planes. If you ask a cleric how they cast spells, then they can tell you about faith in their deity and how they channel energies from the outer planes. If you ask a sorcerer how they cast spells, then they'll mumble a bunch of nonsense that doesn't mean anything, and the wizard will go back to explaining how it really works.
Fey aren't like that. Fey work because of 'magic' and there is no deeper explanation. If your players are anything like me, and you want them to take the fey seriously, then you need to give them a solid origin that makes sense, and which your players can accept. Make them more mundane, like a race of even-smaller elves, with a greater affinity for the sorts of magic that wizards use. Make them knowable. Don't use their nature as an excuse for unpredictable things to happen, because that's the easiest way to make a serious player stop caring.