The binder is simple to play but complicated to build; figuring out pact-making, pact augmentations, vestige synergies, and such can be daunting, but once you've bound your vestiges your options are fairly manageable and straightforward.
The beguiler is simple to build but complicated to play: you make barely any build decisions at all, but handling the minutiae of grappling, debuffs, illusions, nonlethal damage, etc. can be fairly complex.
The warblade is simple to build and to play: you can pick maneuvers essentially at random and still be pretty effective, and anyone who's played card games can figure out expending and regaining maneuvers.
The bard is complicated to build and to play: you have lots of ways to build your bard based on what aspect you want to focus on (music, spells, skills), and the bard's jack-of-all-trades nature means you hit lots of rules subsystems during play (conditions, illusions, music uses, spells known, etc.).
You'll notice that all four example classes are tier 3. It's possible to balance simple newbie classes with complicated veteran classes as long as you're willing to accept varying optimization floors and ceilings--it's hard to either screw up or overpower ToB classes, but bards have a reputation of being weak because they require more effort and more splats to make competitive, for instance.
These are some of my favorite classes to build and play! I really enjoy a solid tier three class. For me, they hit all the right targets.
Also, I think you have it right that WotC may be approaching classes with the "wrong" mindset with regard to Martial = Simple and Magical = Complex.
Frolic and dance for joy often.
Be determined in your ventures.