Nobody is bad for liking a class. Fun is subjective and everyone has different preferences.
So if it's fun for you and you keep playing it, it's a good thing.
But fun and in need of improvement isn't mutually exclusive.
People criticize WHM for good reason and while some of it has been taken care of with EW, like extremely limited mobilty and awkward weaving, WHM has a long history of getting neglected because it has to be *~simple <3~* - by constantly bringing down the skill floor AND skill ceiling so nobody has to feel bad just because they can't play at skill ceiling level in casual content. Although playing it at high level like 95+ is challenging, the fact that WHM is forced to do less the better you get makes it feel braindead. You're even discouraged from using Lilies for healing unless absolutely necessary because they are a dps loss without a transition dump. AST and SCH still feel decently busy at highest gameplay level, especially AST.
Objectively speaking, WHM is "bad" as in poorly designed.
But it can still be enjoyable. WHM is my go to healer for roulettes because it not only gets the job done, it's a freaking dps powerhouse on steroids in dungeons and regulary out-dpses proper DPS classes on big pulls.
I may also occasionally do Ex/ Savage on WHM if I haven't healed in a long time because there is not much to remember. As long as I remember what the boss does, it's easy enough for me to use my Asylum, Lilies etc. accordingly while performing well enough. Not 95+ well, but well enough to be an asset.
AST and SCH has a lot more to keep track of and is not as easy to go back to after a long break from endgame healing.
