Simply because you can play almost equally well, without anything like the same level of computer matchups.
Ivanov speaks out!

Too high match with engines is proof if you are not the world-champion or similar..Usually this kind of talent would show very early on in you chess playing.

I'm no FM, but I've beaten some IM's and FM's at tournaments
Sure ya' have, Rich.

nah the BYP will beat ivanov even if he uses computer engine. The BYP on hybernation studying sillmans books and when he comes back he'll be rubbing us on his mustache.
Hes gonna MOW US DOWN. heck.
So tell me again, how is inconsistent play proof of cheating?
No. What was said was his play is consistent with the play of a computer.

All of this is wrong.
Ivanov was the model of consistency in games where he wasn't being monitored. But in games after he had gone through a metal detector, his play was about 2000 strength.
That was the inconsistency. It later turned out that he was hiding the device in his shoe.
Better, but still slightly off. He did throw a game here or there even when he wasn't monitored closely.

Before his last tournament Ivanov signed agreement they can search him. He refused to show his shoes during his game vs GM Dlugy. This is clear confession. You may refuse testing for alcohol while driving, but you are treated as guilty in such case. The same here.
More or less he will continue to win prizes and laugh until FIDE kicks him out for good.
I just wonder how he does it ?
Ivanov, tell as a secret, I am a little short on cash these days.
The top cash prize was US 200 dollars.