Edits are supposed to improved overall the questions or the answers. It's usually possible to do more than just simple edits like "fixing syntax errors". Keep in mind that small edits might even get rejected in the review queue when they are too small.
I die a little every time I see small edits that are fixing a word and retype it incorretly.
Usually if I see such errors like a missing semicolon or something close to it. It isn't hard to edit more than code snippets. Often people makes typos and it is possible to fix grammar errors or rephrase things that aren't clear. As long as the edit are improving the question without "changing" its meaning. You'll never have problem with the 6 char minimum.
Also, code snippet that are changed in a way that drastically change the algorithm might get rejected too.
I'll add that code edits should not be made in questions and possibly only in answers. As trivial as it might seem, code formatting for a python program could be actually fixing a syntax error. For that reason, people are probably more expecting to see the code in question "as-is" than fixed. If you want to fix the code in a question, post an answer instead.
The 6 char limit isn't a bad thing in my opinion. It's like the 15 char minimum in comments. It will prevent abuse and really small edits that don't really improve much the question/answer.