Agreed. It took me a long time to give up on Mootools because it felt like it made so much more sense. jQuery's tendency for chaining felt particularly gross to me - in retrospect I don't think I was wrong, either.
But the sheer number of plugins that depended on jQuery made it's dominance inevitable. Thankfully we're now coming back out the other side.
'Wrong' often reduces something multi-dimensional to the single dimension of right/wrong.
I think you were 'wrong' in the sense that the most common use case then for jQuery or MooTools was better served by jQuery. As in, you were probably not the most common use case.
But I think you were right, especially considering the current reality, in feeling that MooTools made more sense. Because in 'current-day' web development you can't usually get past understanding the level 'below' jQuery and MooTools (plain javascript/DOM). For example, I've never met a React developer who couldn't use the regular DOM API through vanilla js.
But the sheer number of plugins that depended on jQuery made it's dominance inevitable. Thankfully we're now coming back out the other side.