Topalov referred to San Luis as a world championship in Nor and Gershon's book, as did Judit Polgar and Peter Svidler in New In Chess magazine. Kasimdzhanov said he would have preferred to see a match of 24 games between Topalov and Anand "as in days of yore." Leko is the main one who thought that Topalov should still play a match against Kramnik (as Leko himself had done). Anand notes that knockout tournaments get "bad press," suggests that Kasparov's retirement had perhaps added legitimacy to Topalov's title, and goes on to say "By the year 2015, I hope the chess world will stop going on about the great legacy going back to Steinitz or whatever" hinting at support for FIDE's changes.
New In Chess doesn't tell us Adams' nor Morozevich's opinions although Morozevich's dissatisfaction with FIDE's handling of the cycle is fairly well known.
We have had pretenders to the title who were chosen through tournaments and ONE genuine World Champion chosen that way. Carlsen may find the best move more often than his peers, but like Bobby Fischer, he is wrong about a great deal away from the board.
The World Champions have been:
Steinitz
Lasker
Capablanca
Alekhine
Euwe
Alekhine
Botvinnik*
Smyslov
Botvinnik
Tal
Botvinnik
Petrosian
Spassky
Fischer
Karpov
Kasparov
Kramnik
Anand
(the other claimants are posers)
*Chosen by tournament because the champion was dead.