The old raid system was one raid lockout per week. TD's "advantage" is that it can be run multiple times per week, and that's one of the counterarguments here defending this new system. But what about the time invested? Sure, it would take several hours to clear a raid initially, but by the time the tier was near its end, a good group could knock out RoF / IGP / CoA in an hour. Some TD groups Take an hour, even some guild runs if you have unfortunate rng / are carrying some peeps.
So it becomes a matter of having to run TD half a dozen times each to get the same kinds of drops you can get by spending an hour in the old raids, once they're on farm. And looking at iRoTP right now, we (you, my one remaining foot is inching ever closer to the door) might be in TD for the entire expac. That's why TD is such an awful grind. That "farm" period where competition over loot dies down will never arrive, it's just you versus the cruel rng mistresses. RIP alts, in like the 4th way to date.