Different take: it's the money!
If I can't afford an original 10" Blue note (try $200 plus each for a 'nearly' clean one) I will buy the reissue. The quality of the sound has no bearing on it.. it is just the money. (For the same resaon I have a LOT of Jazz on CD. It is hard to find some stuff on LP) I have hundreds of Jazz reissues because I could never afford the originals. As for Rock, most of the originals are available a lower prices than a reissue. For some that are not, I will buy the reissue ((Captain Beefheart is a good example: "Doc at the Radar Station" would cost as much used (for a not-so-pristine copy)as a new one.. if you could even FIND a used one!))
As LPs become 'all the rage' the supply of used (especially 'classic Rock") is disappearing. Thank Goodness I have most of what I want, and still live in an area with a bunch of decent used LP stores.
Classical music is a different beast altogether, and very very few reissues exist. Classical music has become a desert wilderness IMO.