I'm not saying Lou should be fired. I think the case for him and against him are pretty even right now. The scales likely will be tipped for me this summer.
As owner, if you feel that way, I think you need to ask Lou what his general game plan is for this offseason. If it involves lots of short term fix ideas then I think you'd have to let him go. If it involves a long term philosophy then you let him keep the reins.
The owners are comfortable waiting in the NBA, and I assume they'll be comfortable waiting in the NHL, so I don't expect trading first round picks for 30+ year old players.