Still, even being intimately familiar with the three most popular cameras from the A series, I don't get any of these cameras on a conceptual level. They're bulky,
How can they be bulky if they are smaller than the average 70s camera, and smaller and lighter than a Spotmaitic, which is universally regarded as a very ergonomic camera?! They are also among the lightest 35mm SLR cameras around. An AE-1 weights almost the same (590g) than an OM-1 (510g) which is universally regarded as being very light...
hideously complicated to operate
Takte the A-1, set the shutter speed on the green P and the aperture ring on the green A. Now you're set to go, the machine will do everything.
This wasn't possible on an SLR before 1978 (the release date of the A-1).
Attach a winder and operation is fully automatic.
The A-1 and AE-1P were popular because they were SLR cameras that could be operated as a point-and-shoot camera.
seem to HATE being used in manual mode,
The AE-1, A-1 and AE-1P were intended for people that found operating a manual camera difficult or slow.
and the lenses are only alright
Are you sure? When the FD lenses were released in 1971, an independent Tokyo university did a test with lenses from all major camera manufacturers in 13 categories according to focal length. Over 300 lenses tested. The Canon FD lenses got the top marks in 8 of 13 categories. Even today, internet reviewers that use lenses on FF digital mirrorless cameras, often find out that some FD lenses are topping the comparison or are very near the top.
I have quite a few of Pentax M42, K, Nikon pre-AI, AI lenses, plus Canon FD lenses and most of my FD lenses are good (50/1,8) to fantastic (100/2.8 and others)