Possible reasons:
-Burke has a deep respect for the Flames organization, I think. He was with the NHL while Hotchkiss was still there, and everyone at the NHL has respect for him, so that's where it probably started.
-Recall him with the full page ad, thanking the Flames fans and organization, after the Ducks 2006 win? **EDIT** Ok not full page add, a letter:
http://www.canada.com/calgaryherald/...9-458c1fcfbbd6
-Pretty good friends with Sutter as colleagues, cut from the same cloth. I am sure in talking with Sutter, and especially the Phaneuf trade, he saw how, directly or indirectly, the Flames owners and organization acted, and worked to get that deal done.
This in addition to Burke and his ego, taking on a challenge and having full control. Not much else he has left to do Canada with other team, he's likely not working for the Oilers, and any of the big clubs in the US that he'd like are stable at the moment.
Not making a case for him, but I think Burke would know exactly what he's getting into with the owners here and so would the owners, both if he was considering, or being considered here. He would want full control though, as he had in Toronto.