That's expense and effort laid out to construct a frame to mount PC parts in, and it doesn't even include panels to close it off and protect the components from dust and such!
It'd have to be, in my personal opinion, one of the sillier PC products to have ever been brought to market. I saw some photos a while back of a PC that a fellow had built into a cardboard shoe box. It looked far more sensible and functional than an open frame which looks like a meccano set construction!
Whether or not dust will be a problem depends on the environment it's located in of course. At the very least, with an open system like that, I'd be keeping an airbed pump handy to regularly blow it down clean and keep it looking nice. PCs attract dust that you never knew existed!
And of course there's alway the problem of prying fingers. I f there's likely to be any littlies about, I'd be advicing you keep that open plan PC well out of reach!
But if it's your 'thing' then fine. Me though, nah!!!! I reckon they look silly!