I can see a large chunk of the population leaving simply because in order to raid you need:

A crafting class to 50
A gathering class to mid 30s
A battle class to 50 (obviously)
Two sets of armor if you plan on farming mats since you don't need to be in your best gear.
Stop teleporting, that cuts in to your repair funds
Keep all crafting and battle armor repaired which cuts in to your repair funds.
Make sure to do your leves everyday or you aren't generating new curreny in the economy and topping off your repair funds

Most people who've played WoW for 9 years are just gonna say "holy hell! all i want to do it raid!"

I personally find the crafting/gathering in this game boring as hell, and if i could help it, I wouldn't do it. At all. Ever.

For people who just wanna craft, they can do that. For people who just wanna raid, they pretty much can't, it's locked behind crafting since you need it to sustain your repair funds.