It's not raiding per se that's the problem. Raids have always been a big part of EQ, it's where the epic feel comes from.
The problem was raid itemization. The raid gear you got from completing an expansion was so good that challenging you in the NEXT expansion required much tougher encounters. Which dropped gear that was too good, etc.
As I recall, it started in VP, the designers basically dared the players to breach the zone. If you DID get in they promised "GM-quality gear". That should have set off alarm bells right away, getting GM-quality gear is something that should never be under player control.
It became a vicious cycle, and now it's at the point where the designers have to cockblock the top guilds to slow them down at all. What reasonable challenge can you throw at a well-honed, well-geared machine like Afterlife? If you remember, once Rathe was "retuned", 5 guilds beat it in the span of a week.
The other problem with the gearflation is that there's really not that much difference between the top guilds, skill differences have been dwarfed by gear similarities. There's no way 20 guilds should have been in Time BEFORE the next expansion.
Where this affects casuals is that top-end players are accelerating through content so fast, the gap between casual and uber has been increasing. EQ is splitting into two distinct games, and designing for both is going to be difficult. This even effects class balance, I can't count how many times someone as told me I should be soloing in BoT, because they have seen other BSTs tanking the giants NP.
This, of course, ignores the fact that these other BSTs may be Time or GoD-geared. Yet if someone decides that "Beastlords tank too well", no doubt I will get the smackdown also. It's happened before, my wife's 30 Enchanter got nerfed because of what chanters were doing in PoP.