The poll is biased -- implying that OLD
erer winning a slam means that he has not declined. Federer has declined -- FACT -- no need for elabloration, any rational tennis fan who has followed Federer over the years can attest to this. Winning a major at 31 is merely a testament to his greatness, that despite declining he is still good enough to be able to compete with players 5+ years younger than himself.
People shouldn't take Sampras's words at face value -- don't know what he was trying to imply here, perhaps he was trying to quell doubts about Federer's motivation, or perhaps he was trying to denigrate what Federer achieved in his prime -- I'll give him the benefit of the doubt however. However, it is rather ironic. Remember Sampras is a player who in 2002 argued that he had not declined and was playing the best tennis of his career
. One's success is related to the degree of confidence one has -- if a player starts admitting to themselves that they are not as formidable as they used to be, it can be detrimental to their confidence. Self-belief is a HUGE and PIVOTAL factor in success at this level.