I'm not saying Detroit is an ideal situation, but at the same time it's not the worst for a coach. A bad team is not equal to a bad situation for a coach per se. IMHO, a team with unreasonable high expectation (Nets) from media and fans, or a team with uncoachable stars (Lakers for both) is bad for a coach.
Otherwise, when a coach has the opportunity to exert his own way of coaching, it's all good even though it's with a lottery team. Take Doc Rivers as an example, he won one Coach of the Year with the Magic, and got the chance with the Celtics after his stay with the Magic. Granted, Celtics was not that good either when they hired him, but still.