1. He probably is asking too much.
2. Some clubs probably completely ruled him out for a few reasons.
3. No matter what, he will be a distraction due to the media wanting controversy.
"Coach, do you think Colin will kneel this week?"
"No."
"Coach, how about the following week?
"..."
"[Insert random player], how did you feel about Colin kneeling/wearing those socks last year?"
4. While he did have a good statiscal season last year, there are fears that he was part of a gimmick offense and that he never really improved his game.
I can't see Dallas being interested at all. We have Dak, a small but knowledgeable backup in Moore, and potentially Romo if you believe that.
I would bet most clubs would rather sink a season with a lesser QB than sign Kaep.