Amazing that it have only been 10 years. I remember when i learned and focused on mootools because jquery seemed just so far away from actual js while eating away, then valueable, performance.
Back when I was learning javascript (2006/2007) it seemed like Mootools was for people who had a good grasp on the language and wanted more from it. I appreciated this, and still think it's better at this than jquery.
I wish Moo had gotten more attention over the years. I get why jquery has done so well, but I don't like its methods.
jQuery won the war, in the end, because it catered to the 'get it up and running now' crowd over the 'do it right' crowd. It was always easier to understand off the bat, especially if you aren't a trained developer, while MooTools makes for a more long lasting, quality codebase.
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.
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.