Well. You may not see it this way, but to me there's a rather big difference. Usually when people talk about RH 'causing grief' and 'UNIX design philosophy' (sigh, if I had a nickel for every time...) they're talking systemd. Yes? Well, sure. Lennart wrote systemd, RH is fairly solidly behind it these days (though note it wasn't at first - Lennart had to sell systemd inside RH about as hard as he had to sell it anywhere else), and quite a lot of people don't like it.
Fine, it's a free world. But that's ultimately a technical argument. We didn't put systemd under an RH CLA. We didn't issue press releases prematurely declaring that it was taking over the free world. It's a freedesktop.org project, you don't have to sign your soul over to RH to use or work on it, it has plenty of non-RH contributors, and it got integrated into non-RH distros through their usual processes for feature review.
I don't usually actually have any problems with Canonical's engineers, or their projects, believe it or not. Of course there's the whole Wayland/Mir mess, but that's kind of an exception (and even there the main problem is down to management, not engineering). The stuff I don't like from Canonical invariably comes from management and/or PR, and (again purely my personal opinion) ultimately derives from Mark and his poor-man's-Steve-Jobs complex.
I don't have any particular problems with Snappy as a technology. Heck, a couple of things about it might be better than Flatpak (I don't know either system in much depth, just broad overviews and the specifics I dug into for this kerfuffle). From a purely technical viewpoint - if you ignore the publicity, and the problematic influence of snappy being under the Canonical CLA and the server end being a black box - it's perfectly possible Snappy could turn out to be the best answer to this particular question. It's certainly not a Wayland/Mir situation - Snappy and Flatpak both have fairly complex histories and predecessors, but whichever way you cut it, they've been around about as long as each other.
The issue I have is specifically with *this press release about snappy*, and more specifically with the way it vastly overstates snappy's current capabilities, and the way it strongly implies that snappy already has substantial cross-distro buy-in. Taken together - and if you look at the stories that came out of it, which Canonical PR *certainly* was not ignorant about, especially given there was a press call - this comes off as an attempt to effectively pre-empt the whole process of building consensus around a solution by giving Snappy such a strong press push that everyone just has to fall in line behind it, regardless of the fact it's not remotely *done* yet and there are other options that have already been trying to build support the right way.