Murali, who took 68 wickets in eight matches during the course of the voting period at an average of 17.47, failed to make the team with the spinner's spot going to Australian rival Shane Warne.
"A few people are not that keen on me because they think I am not bowling properly," said Muralitharan who holds the world record for Test victims with 532 wickets.
"That's the only reason it can be, but it's disappointing for me."
Warne, who stands at second on the all-time list with 527 wickets, only played half the year after finishing his 12-month ban imposed for failing a drugs test on the eve of the last World Cup.
"It happens sometimes that people are not favourable towards me but they do not have to judge that - they have to judge how I have performed during the course of the year," the Sri Lankan told the BBC.
"I am surprised that someone who didn't play for six months did get into the side.
"If you take Warne's total career he should be there but if it's about one year's performance he should not because he did not play for six months of that time.
"I don't need more awards - I already have the world record but I was disappointed on the night."
Defending the decision, the selection panel chairman Richie Benaud said: "Warne came back and made an immediate impact with 36 wickets in just five games and deserved his place as the first spinner.
"Leading wicket-taker Muralitharan was unlucky."