I've never understood cases for tablets (and phones for men, at least, who don't have to put it in a purse). You have this nice shiny device with a great finish that looks amazing... and then you're going to lock it away to preserve it while not enjoying said finish nor possibly the kickstand for what? So that, when you're done with the device, you can take one last look at it? Maybe so that you can sell your obsolete device for slightly more than you could have if it had a few scratches?
I can maybe see it justified for people who are just absolutely clumsy and will nick it and bash it all over the place but, for the average user, cases are just a way of extracting another $10-40 from you.
Well, I do have a case, but that's for my iPad Air and if you have held it, you would probably appreciate why I opted for it. The other option would have been to (1) live with a scarred iPad and/ or (2) if one did not opt for the Apple Care facility, then potentially face a very high bill to fix a damaged tablet.
That said, I don't use a case per se for my Surface 2. In many ways, I find it more rugged than the iPad Air (and iPads in general). But I do carry it around in a soft neoprene cover.
As for my phone (Nokia 720), I don't carry it in a case, and I have already dropped it once and have succeeded in warping one of the edges slightly. I did consider a Nokia case for it, but I just have not gotten around to getting it.
I don't have any case for my Nexus 10 except for the outrageously priced Google issued cover (which I bought because it looked nice). But then again, that tablet rarely leaves my bedside table.
I do have to care for my gadgets because I depend on them to do most of my work. And while I don't molly-coddle them, I try not to abuse them either.