The best way to see how it looks is to try it. :) Install + View CV shouldn't take more than 30 seconds in total if you are already logged on to LinkedIn.
No, most people don't just install stuff that lacks even a basic screenshot. The lack of any visuals asks all of us to give you too much credit for design quality in advance. There are risks to installing chrome extensions, on top of the time required to do so, and most online CV generators are hideous. If you refuse to show what yours looks like visitors have to go with the statistics and say yours is probably ugly too, hence no install. I can't imagine why you wouldn't show one, but it's your call.
Since I don't want to use my own data, I would have to invent an imaginary profile and fill in all the data (practically write a full CV with fake data). Haven't found the time to do that yet since I didn't think it so important. Obviously it is.
I agree with the OP. I was interested to see how it looks, but I'm not going to install to determine that. If a tool doesn't show examples, it's usually because the examples would dissuade people from using it.