Re: quality..
some people clearly like something about vinyl (handling discs? bigger artwork?) enough to cause a revival.
I do think this is part of the story: the rituals and practices heighten the anticipation of the moment. The fact that many of the rituals are tactile (e.g. the special way they wipe the dust, the care with which they lower the arm) is important. Regardless of what it may (or may not) objectively do to the music reproduction, it really can change some people's subjective enjoyment. (Compare: tea-making rituals).
And then behind that is the opportunity for geekery: to know more than the average person about selecting and matching components for the "best" reproduction, to read endless magazine articles about the specs of the latest equipment, agonizing over whether to upgrade now or hold out for better: for many of this type, the equipment is more important than the music.
And third, there's the lure of exclusivity and collectability: vinyl, especially older vinyl, is a physical artifact that exists in finite quantities and is found in physical locations. The search for a rare copy in good condition of a particular edition can itself be rewarding in a way that finding an MP3 online really is not.
And to be honest, I have no problem with people who enjoy vinyl in any of those ways, so long as they don't insist that their end result "must" be better than mine and that I'm doing it wrong by listening to MP3s on a tiny SanDisk through ear buds to drown out the noise of the lawn mower.