The reason Blizz gives on why CRZ was implemented depends at what time the question was posed.
Originally announced as a way to help out 'dying'' servers (it didn't, it only took away the few advantages those servers had), it soon became to 'bring people into the world to Group with' but when the fallacy in that was also made clear (The Shattering/Cata deligently removed any and all World content you 'needed' others to Group with for) it was 'to experience fierce competition over Nodes and Rares (an aspect that doesn't really compute with the falacious 'End of Game Is King' doctrine CG c.s. have spouted but okay).
Given that Blizzard is on record on saying
Providing an environment where players can compete in the spirit of fair play is extremely important to us
and in regards to Twinking and (recently) Pre-Mading in PuG Battlegrounds made similar sentiments, it would be consistent and make sense, certainly in the light of the rediculous Power Creep since esp. Cataclysm, to solve the issue the OP and others have with the fall-out of CRZ and similar stellar designs.
Personally I'd be in favor of a different solution
Said before, will likely be said again:
phase the Zones in half, characters up to +/- level of the Zone in one phase, those above in another
That way world PvP would be meaningful for characters at all levels, and those who like feeling powerful by imitating Kingslayer Orkus' evil twin can wipe out towns as much as they want without affecting levellers. A win-win situation.
as it would basically prevent 'cheezing' the game and still allow people to engage plenty in World PvP , but sadly, most notably amongst the Too White And Nerdy-crowd that likes to pose as hard-butts by ganking helpless oppnents yet whines about (possibly) not being able to cheeze the game as much, not everybody shares this sentiment - even though it has been suggested way back in Wrath as a positive
use of phasing.