Why does everyone play the petrosian against the KID

Everyone? In the games I have played, few play 6..e5.

And as one that plays the King's Indian from both sides, it is mostly GMs, IMs, and FMs that play the Petrosian Variation against me, and amateurs almost never do.

As White, I don't play the Petrosian.  I play either the Exchange (7.dxe5) or the Gligoric (7.Be3).  The latter I tend to play more against those that delay or avoid ...e5 and the exchange against 6...e5 players.

How's your record with the exchange ?

This is a strange statement. In my experience, the Petrosian is one of the least likely lines seen against the KID. Granted, the Saemisch may be even more rare in Class tournaments. That may be because the Saemisch is one of the most strategically complex lines White can choose. 

One of the great things about the White side of the KID is that there are many different ways to get a slight edge. The problem is that most of those involve the same basic race between Black's K-side attack and White's Q-side pressure. Quite often, white wins on the Q-side but loses the game cos he gets mated on the K-side.

I only started playing it recently.  Used to always play the Gligoric (6 wins, 2 draws, no losses) and the Four Pawns (over 50 games, roughly a .500 record) prior to that.

With the Exchange, I just have the one game I posted previously.

EDIT:  Hmmm...can't seem to find it any more.  Reposting the game here:

I can think of maybe 2 times that I've faced it as Black (being a King's Indian player myself).  I know one for certain that I won.  I seem to recall another that I drew.

As black, always happy to face exchange KI...

Clearly not a critical test and black can choose the variation he wants if he/she wants to draw or a fighting game.

In tournament, i faced few times exchange, almost 0 Petrosian.

But on live games, Petrosian and Exchange are probably the most played against me, with the Saemisch.

Petrosian is also my personal preference against KID as White. I played Saemisch, g3 systems and even Hungary variation against Black before but I didn't get good results. I played many games with Petrosian and I really like it.

@Poucin, your experience is almost certainly not typical since probably most of your opponents who play the Exchange are lower rated and mistakenly hoping for a draw as White. Stronger players looking for a win often choose the Saemisch, but that's almost never seen at the lower levels.  The Petrosian seems to be more popular in the 2000-2400 range than in lower levels of chess tournaments. The Mar del Plata is quite popular online from what I've seen.

The Fianchetto variation became more popular with club players after Avrukh's repertoire book came out, but I don't think many KID players were scared off by the Fianchetto.

I not like Petrosian or Mar del Plata for white side.White may have  advantage, but I not want to see my king mated  on king side when my pieces has  ruined black queen side.My weapon aganist KID is   Saemisch.I   build up solidy and see what black want to do.There is some variations where i castle on k-side only if am  sure that i have restrict  black counter play.There is also lot of cases where i  play g4 ng3 h4 h5 bh6 and mate black king.I see Saemisch as deep and flexible system based on understanding and putting opponent in uncomfortable position.