It's not that (quietness or blending), it's just that, heck,
I can, or at could* sing better, quality / tonality wise, given monitoring of a decent sort, and I'm not much of a singer.
*My range, never great, has suffered quite a bit after age 65. :-(
Then again, quite a few lead singers for quite a few better known bands are (or were) not all that great either, IMO, but sometimes the bands made up for it in other ways.
I'm relatively new in listening to the genre myself. AFAIK, it pretty much began with
this band from the late 80s/early 90s. Note the vocals have a dreamy sound. Then, as other examples, the early 90s brought
this band and
this band and so on. The vocals are similar. But, yeah, I can understand why other listeners might not like it.