A frag trade or sale is still a business transaction in nature and thus it's clearly a mutual thing. A buyer should ask about warranty before purchase and cannot claim warranty if not being explicitly spoken of. The buyers have all the chance of inspecting the coral frags, including not buying it if it does not look right (actually, even when it's perfectly looking.) There's no reason to ask the seller to assume responsibility of the buyer's inability to keep any frag, not just SPS, as long as the seller is not intentionally hiding info. or known issues. The seller should not be the one to educate, it's the forum's job. The seller should inform only the information requested and ask no further. Imagine, when Jhale, prattreef, come to get macro algae from me and I asked them his tank size, lighting, SG, pH .... GM sell you a car without asking your driver's license, you pay extra to a driving school to learn how to drive. GM should not sell a car that known to blow up immediately but should tell you what the warranty is(I am sure it does not cover bad driving skill.) Hence, I should not hand out infected mushrooms.
These type of questions have been around for as long as I am in the club but yet I have not seen a dedicated forum of "Before You Buy Any SPS Read This", "Before You Buy Anything Reading This", "Before You Enter the Hobby Read This", 'Before You Enter MR Read This(cause you'll addicted to so many SPS, hard to keep stuff and thing that usually only money can maintain them safe)" Instead, every time I open Manhattanreef web site, the first pic is usually something many members cannot keep yet so beautiful that everyone is drawn to get(I hate Jhale for this, hehe.) There are not even a slightest inclination of anyone to remind them with a disclaimer. The site is not wrong in putting the beautiful pic that have lured so many of the unaware crowd-it's the buyers' problem of not asking the prerequisite of entering MR, the hobby, the Fish realm, beginners' coral then advanced SPS.