Less caps or higher caps

I perfectly understand caps on block, dodge, dmg reduction, ressource cost ,crushing blow and all sets(seriously this affix is overpowered). But why is there caps on push the limit, total hp/mp, , …?
Let’s say there is no cap on attack speed. Max aspd (without sets) is 645 (crystal affixes) + 615 mythstones) + 30 (eternal pet) = 390% which is around 3 times faster than +60.

Things that in my opinion would be really broken (using “about obsidian” topic’s rules for crystal affixes):
Skills/talents
Total AR
All procs

Push the limit increase ur cost skill… when u use any resource system, like fury or energy, u cant use special skill because not have mana if u use 100++ push the limit…
Same at pvp, if u use to many PTL, u cant use skill often, no mana = no damage… Better to use other damage increase affix…
Basically, PTL not have cap… But ur mana/energy or fury make that affix capped

So PTL + fury+primary skill = OP ?