You don't crit for much no matter how much your Crit Damage is if you ignore your main stat. If you don't stack Crit Chance and Crit Damage, and IAS having so low values on items, what else is there to stack? There's only 4 damage stats. Base stat, Crit Chance, Crit Damage and IAS (aside from weapon damage). Crit Damage is only powerful if you have good base stats along with good weapon damage. Crit Damage / Crit Chance alone is crap.
But the thing is how much more powerful the average crit chance/crit dmg rolls combined with an average main stat roll is than a maxed mainstat with ias for instance.
If you have near perfect main stats and a high base damage against someone with an average (say 40% less than you) main stat/base damage and average crit stats (somethinglike 30-35% crit chance, 180-230% crit dmg, which isn't even close to max), you'll probably do crappy damage (instead of similar damage) because of how crit dmg scales with crit chance.
That's the issue I think people have with these 2 stats (iirc even Athene said this was a problem).
The only real 'issue' is that stacking crit chance and crit damage is the only competitive way to build your characters at the moment. Even if you have zero skills or passives that interact with crit, crit chance and crit damage is still the correct way to build.
The main difference, compared to attack speed, was that attack speed was clearly the best way to build from the very first item, while crit isn't obviously the best way to build until you've gotten a handful of items.
I'm not saying there is 110% a problem, let's nerf crit chance and crit damage. I'm just pointing out something worthy of discussing, and giving my personal insight on what could be a problem: having only 1 viable dps-route, because that one is easily (even with crappy rolls) 4 to 5 times more effective than the other dps-routes.
Well without creating balance between the stats there will always be one route that is more viable than the others, that's just the way it is, the only solution I see to the supposed problem is for Blizzard to add more diversity when it comes to gemming, give the option to use something other than 100% crit damage that is at least equally good.