I've skimmed over this thread title quite a number of times over the months thinking it had to do with ROM flashing actually having a fatigue-like effect on our hardware so I had to poke my nose in.
To continue from where the OP left off: I certainly hit that point with 2.3.5 on my EVO Shift and then again on my Galaxy S4. For me it was first a matter of trying to find the right 'fit' for me since running any unmodified technology is just letting unharnessed potential go to waste, but I do get to a point - and I remember it very specifically with my S4 - of just sitting there at the Android Development forum staring at all the ROM releases and just being like, "Meh." But every time I'd return to stock I'd just get this overwhelming "dirty" feeling and would get caught back up in the thought process of "Ugh, where to start to get rid of ALL of this **** I don't want, need, and already have preferred alternatives for?" Anything along the lines of customization for stock seems so limited, unsatisfactory, and really just unacceptable in my eyes.
I don't remember what ROM I settled on with my EVO Shift; I do know that I couldn't even find my old files when I had to wipe it to let a family member borrow it and just flashed the most recently updated one I could find. I've been running CarbonROM on my S4 for a few weeks after trying every major 4.3 ROM and just not finding a good fit for me, and I am very much enjoying it despite it still having issues; none of which are dealbreakers for me and I know will be addressed in the future. Flashing a daily every week or so doesn't seem outside the realm of reason with dirty flashing, OTA updates and utilities like ROM Toolbox to get me back up and running in 30 minutes or less, and finding new developments/tweaks I can implement are a constant source of (mostly) entertaining and beneficial endeavors. Having a modified ROM allows me to have very little of what I don't want and more of what I do - or at least provide a MUCH cleaner foundation to have my phone how I want it.
I have the same problem with the IT industry and computers shipped by Dell, HP, etc. The first thing I do is wipe them completely, customize my OS installer of choice, restore the software I've come to prefer and support over the years, and then never touch it ever again unless something fancy-shmancy comes along that piques my interest to instill enough motivation to give it a try. Stock is just so ugly, restricted, sub-par and half-assed for my liking to even consider "just dealing with it."
Then again my fiance of three years - she's had plenty of time to run away - regularly reminds me of being a control freak, so I'm sure that plays some role in it all as well.