The 'inconveniences' of Classic kick in full throttle past 30 and hits a special place as players approach 50. Recall 5 man runs with random players, and at mid to high level range how CC matters. Recall -for example- ZF (Zul'Farrak) an instance many, if not all, will want to run for Carrot on a Stick Trinket as well as great upgrades for that level range. Also, recall how last boss need Mallet of ZF to summon the boss. Now recall getting that Mallet
ZF is just one example, chain wiping in 5 man due to clueless players who then leave mid run is another.
That is why I predict half the players who never played classic will quite before 50 and the other half never make it into end game content -let alone see 60.