And from a design perspective the job's gameplay suffered quite a bit. You can claim that people adjusted to it, and that much is true. Poor implementation remains poor implementation, regardless of whether the players adjusted to it or not. Hence why the OP made this thread.
Since you are asking for explanations, I'll indulge you:
The base design of BRD and WM as implemented clash because cast times and reliance on off-GCD abilities & procs don't mesh well. The intent of the changes also doesn't make much sense, since WM is introduced so late in BRD's relative "life" and implemented in such a ham-fisted way that it doesn't feel like natural growth of the job. It's no surprise that people who are just picking up the job also seem to be saying that the change is too abrupt and feels clunky as hell despite the nice DPS numbers.
If the devs want to stick with WM, then WM has to do more than just add cast times to shots. It has to change procs and other mechanics attached to BRD, maybe even go as far as change the effects of the various shots while active. If they were to do this, then you could see its inclusion as something truly added to the job instead of something tossed in for the sake of introducing change.
If that's not going to happen, then WM has to be reworked to limit its effect on the job's gameplay so that it feels more natural to the job, be redesigned for the purpose of same, or be outright removed and replaced with something else.
The last, and most work-intensive option would be to change the base ARC and BRD mechanics to fit better with WM (as the OP mentioned, removing potency from utility shots and changing the way Bloodletter procs work would go a long away in helping).