...but, in my experiences, I found dual wielding to be fine. But only if you're Fury. I found that having two weapon swings meant having twice as many chances to crit, which led to lots more Flurry procs. At level 50 with two blue 1h swords, my kill speed was just about the same as when I used an epic 2h axe. And I wasn't even specced into the offhand damage talent. If I got a good string of crits, I could smack mobs down in 15-20 seconds, and easily hit Bloodthirst every time it came off CD.
Most people who have spent years playing massively multiplayer online games will tell you that there's something special about the first one you played, too—and WoW was the first for many people. You can become so swept up in the uniqueness of your first experience that you overlook many flaws. It's likely many look at WoW Classic with rose-colored glasses, just as many simply forgot which features were added when. And some of today's WoW players may be too young to have even played vanilla WoW as it once was.