Sure someone has. Someone has surely written to Ebert to tell him that Shadow of the Colossus is equal to any great piece of art, and that convinced Ebert he was right because if he were wrong, wouldn't other intelligent, educated people have told him so? ("Intelligent and educated" here being people who appreciate art instead of wasting time on games.)
I remember seeing a reader-submitted email on Ebert's Chicago Sun Times site years ago in which the writer was expressing support for Ebert's (illogical and obviously wrong) stance on games. The writer used, as part of his defense, the bullshit argument that art evolves, but what makes an FPS a great FPS, for example, would always be the same. That's obviously nonsense to anyone with any experience playing FPSs (or any other game genre), but it supported Ebert's stance so up it went on the site.
I realized a long time ago, after reading everything Ebert had to say up to that point on the issue, after watching him backpedal to other arguments when it was clear he was wrong in the preceding argument, that Ebert's stance anti-game stance just sort of sprung into existence more or less fully formed. His lack of knowledge or experience on the subject be damned, he's made up his mind. When he discusses the subject now, he's basically looking for things which support his stance and poopooing/ignoring things that don't. There's no convincing (or even discussion with) someone like this. And yet he, and other people, keep wasting time talking about it.
Really, the guy, like everyone on the planet, is fallible and clearly flat-out wrong in some areas. (His bizarre issues with David Lynch's earlier films are a good example.) Why can't this just be one of them? Why can't the world just accept that he has some sort of mental block he isn't going to get past and let it rest?