I don't own one, but I'm a consumer like everyone else.
I think the OP's basic point is that compared to bikes of similar price, the value to money isn't quite there. Back when the 650s were first being sold and you could buy a whole sidecar rig ready to go for a 3rd of what it might cost to build one, they were pretty intriguing. If it then turned out to really be a POC, you weren't out a huge amount of dough.
The quirkiness and breakdowns can be construed as "character" when you're not breaking the bank to buy the rig. At $12-16K things like leaking trunks, wonky speedos, and broken final drives should be unacceptable.
The ladies used to check me out...now they just keep an eye on me.