Reason 1: I just can't seem to kill the thing.
I bought her for £150 taxed and tested to use as a work horse because she can go 100 miles on less than 4 litres of petrol. And for a while she was just used as a souless vehicle to save money with...but then things slowly changed.
I constantly abuse the poor thing, I ride her as fast as she'll go down muddy lanes and when things wrong, we leave the road enter the ditch or hedge and with any luck smash our way out legs flailing and continue the journey. There's no worrying about broken fairings, bent forks or scratched paint. You just keep on riding.
I strap anything I can to her that needs moving. I've carried 32 inch Tv's, fire wood, scaffolding, welders. Once when my mates C90 with no engine needed transporting, I took the wheels off and carried it on the back of my C90 to his house. Try carrying a BMW GS1200 on the back of another GS1200!!!
People laugh when I say that my maintenance schedule is once a week I put petrol in it haha. But apart from changing the engine oil every 1000 miles, that's it. I've never lubed a control cable, greased a nipple or even washed her. Sometimes I put some engine oil on the chain but when it's only £15 for chain and sprockets....it doesn't matter if I don't.
Reason 2: Nothing comes close to one riding on ice.
Below is a video that shows what happens when the UK has snow. There are no bikes on the ride, most 2 wheel drive cars are stuck and the 4x4s are still having trouble....and then there's the C90.
The video says it all...the centre of gravity is so low and the tyres so small that it just doesnt loose grip, and when it does, you just put your legs out to use as stabilisers and power slide:
I've riden UP the green ski-run at the Alpe D'Huez ski resort and played around with the snowmobilers.
I've towed a broken down C90 on sheet ice over mountain passes with a 3rd C90 pushing from behind as well
Reason 3: You're instantly seen to be friendly and down-to-earth
Here's an example a situation I was once in: I was riding through Belgium in winter when it was about 0 oC. I called in at a campsite (which was closed but had an open pub) and asked how much camping was. The owner was intrigued and walked out to have a look at my bike, as soon as he saw it he burst out laughing and called his customers outside to have a giggle too. Then he asked where I was from and where I was going, I answered "England and I'm going to the Czech republic". From that moment on, all my drinks were free and I got free pizza and crisps. In the morning I had breakfast and a hot shower round his sister's house and they even gave me some thermal trousers and a warm jumper which I still have.
Don't get me wrong, I know that they may have thought I was still a "Hero" on a shiny GS1200 and maybe a free beer, but I reckon I may not have got the jumper or the shower.
There's just nothing pretentious about a rusty C90 and no-one is ever going to think "that guy has loads of money and thinks he's really cool, maybe I won't talk to him"