I must be odd, I’ve always liked riding in the rain 
Not sure why, maybe it’s the chance to learn more about the bikes ability, and to improve my own.. or maybe (as I’m from Grimsby) I’m part haddock 
Only recently have I become a rider who chooses when to ride, previously my bike was my transport, sun, rain, snow, ice.. it never bothered me, I just wore the right kit (often work-issue dayglo waterproofs
).
So far as bike issues - My first bike, a Simson S50B1 died on me in heavy snow in 1982 (and is still awaiting a refurb). I’d fit tubing over the HT lead on my CG125 and liberally apply leccy grease to maintain the spark in heavy rain, and I fitted a home-made deflector plate to the front plug on my SV650 as it’s exposed nature meant it’d pop and bang and run on one cylinder during wet weather (proper mudguards or at least a fender-extender would likely have helped too). Otherwise I can recall few wet weather related issues over the years.
Two pairs of second-hand Gore-Tex Frank Thomas have proved fantastically dry, even walked through a stream in em on the way to watch from Barregarrow Bottom at the TT without getting wet. The work waterproofs (widely available from workwear stores) have always been fab, I usually replaced them after two years daily use. Hand guards do a good job, but I’ve often fitted handlebars muffs too, ugly but ace. The missus uses cycle overshoes when we go across Europe, they’re neoprene, slip over normal boots (we generally ride in ‘street clothes’ so far as jeans and boots) and they work well adding both warmth and a level of waterproofing.
So far as the bike getting dirty.. never worried about that, bikes are a tool to me, in my mind they should be used, getting dirty means you have the chance while cleaning to get to know it better. I’ve found that intimacy helps keep the bike in good order and provides another level of confidence for me when riding.
So for me, wet or dry, bring it on, I’ll always prefer to be on my bike. 