Tendulkar peaked in 1998, when he made those magnificent twin ODI centuries against Australia in Sharjah. It has been steadily downhill since then, with a few sparklers off and on, but that has apparently been enough for our media. Sample, how in the 1999 World Cup, when he came back after his father's funeral and slammed Kenya (whose bowling attack could not have been better than MIG Cricket Clubs at that time) for a 140, the media raved about him. That he did not cross 50 after that even once was characteristically glossed over. (It's not that failure is to be held against him more fiercely than others ; it's just that his success could be examined more closely).
Forget being the world's best batsman, Tendulkar is not even India's greatest batsman today. That distinction goes to Rahul Dravid, by a mile. No-one has won India more matches with the bat than Dravid has, not to speak of the matches he has saved. Both Laxman and Sehwag have played more significant, match-winning innings for the Indian team in the last 5 years than Tendulkar has (the man-of-the match awards clearly tell you that). So, why is he considered our greatest batsman.