Before I begin with today's real topic, a brief thought about this weekend's Dehydrated Double: I'm sort of intimidated by it. There, I said it. I haven't even the faintest idea of what to expect out of the thing. Though I've been told that I've done 100+ mile rides, I can't remember them. My benchmark "long rides" are in the 80 mile range; this is 1.5x those.
So, I've seen a couple of wheels lately that look like they were ridden through Superfund sites and then instead of being cleaned off, they were dunked back in for good measure. This is not good. Having managed many construction sites, I know what mud can contain - about 100 things that end in the suffix -ene or -one, like toluene, benzene, acetone, etc. There is also often lots of ferrous metal in mud. This is in addition to the fantastic hydrocarbon sludge that prevails on the roads we ride. Add to this the salt and general grit that roads are covered in this time of year (and, thanks to public budgets, aren't likely to be relieved of) and not washing your wheels makes their life akin to living in a HALT (Highly Accelerated Life Test) chamber. One wheel that I saw had corrosion on the spoke surface at each spoke crossing, and on the spokes at the hubs - the metal in the mud rusts, and as Neil Young told us, Rust Never Sleeps. Leave rust on stainless (spokes are stainless) long enough, and the spokes will rust.
Stainless is very highly rust resistant. It is not rust proof. The most rust resistant stainless is type 316. 316 is used most prevalently in marine applications for this reason. It is also by and large the weakest type of stainless. I've seen premium quality type 316 fasteners turn to rusted globs of crap in one Caribbean season, thanks to lack of washing. A simple rinsing would have done it, but the ultra saline conditions in the Caribbean water, plus the making sunshine and heat, had their way instead. These parts should have lasted for years and years, instead of "year." Sapim spokes are made out of 18/8 stainless, which is stronger than 316 but less corrosion resistant. It's the right choice for spokes, but you have to wash it every now and then.
If you leave your rims dirty, they will wear out faster. Muck and abrasive grit migrates onto the rim track, and every time you break, it's like taking a belt sander to your rims. Commuters in rainy, hilly places like Seattle expect not much more than 3500 miles out of a set of aluminum rims - that's about half a season's worth of riding for me. My mendoza line for rim life is 10000 miles at the very least, the variance being purely down to the amount of braking one does and the sludge on the rims when one does it. Also, my guess is that if your rims are skanky, we don't even want to know what your pads look like. So there's that.
A chain that's kept far more meticulously clean than mine is will probably last three times as long as mine will. Life's too short to clean your chain that much, so I replace mine often. Price of doing business. If you neither clean nor replace your chain, then your shifting will be bad and you will wear out cassettes and chain rings (which are expensive and getting more so every year) far far far more often than if you cleaned or replaced your chain.
I'm not Johnny Retentive about keeping my bike ultra pristine clean, so when I categorize your wheel's condition as "disgusting," it means something. Sometimes it's hard to keep your bike clean, like if you live in an apartment or something. I wish there was a different answer but keeping your stuff clean will make it last longer. It's important.