There's just something inherently peaceful about coding to a 508 standard. In a development world of unknowns - whether from the client end or the tech stack side of things, always ensuring I'm coding/presenting to Section 508 standards always leaves me with a sense of accomplishment. Like, I know/hope a section of our audience or our client's audience will have as consistent and as rewarding of an experience as other who may navigate the site but also that, underneath, nothing is an ugly mess.
I kind like to look at our site and others in No Style Mode. It really just lets me see how things stack up (pun absolutely intended, get out) and it makes me stop and things about how I've structured the document from a good, standards-compliant standpoint. Being a Computer Scientist, I have lots of standards that I like to say I comply to but often don't (DAE eat too much gelato?).
(Oh, I'm using WAVE, by the way. Man, I love that tool.)
While 508 may be required by government entities and some large corporations but not necessarily be required of small sites/businesses I think it's best practice to get in the mindset of developing for standards first and visual second. That's not to say design/style-visual candy takes a backseat. That's not it at all.
It's that I have the sense of accomplishment of knowing that my document is structured to standards (not always, things happen) and that I, because of this, can also ensure a better web experience for those who consume the web differently.
I'd be lying if I was saying this is all altruistic because it's not. That satisfaction from passing standards checks give me a little endorphin boost, but, I am glad it serves a greater purpose, too.
Once everything is standards-compliant, I can put on all the candy and frosting (and Gelato!) that I want and know that when I strip away all the fancy adornments I still look good naked.
Bonus: Here's a good spot for some tasty treats in our neck of the woods.