Why Didn't Avery Testify? Not a Sign of Innocence

I'm not sure if Steven Avery is innocent or guilty (it's a very compelling case) but I will say that the fact Avery didn't testify in his own defense is a pretty good sign that he's guilty. Think about it - If you were truly innocent and you also knew that the prosecution's case was pretty strong - and it is strong, minus the rare circumstances we have here in which LE has a genuine motive to plant/manipulate evidence to convict Avery - wouldn't you testify in your defense? Wouldn't that be an easy decision? I know I would. Even if my counsel advised against it, I would overrule them and do it in a heartbeat. I'd be eager to have my side of the story be told - not just to rebut the prosecutor's story, but to tell my story for the first time. I don't even recall a discussion among Avery's lawyers about whether or not they should do it, which is a little strange (since other tactical decisions behind the scenes were shown on-camera). And I know legally, a jury can't use a defendant's decision not to testify against him, but from an objective standpoint of innocence vs. guilt, I think it's fair game for the rest of us. Thoughts? Was there anything said by Avery or his lawyers as to why Avery didn't testify?