Usually when a topic is locked it is either because the conversation has degraded to an extent that no good will come from continued participation, or it is done because the topic has run it's course and no other useful information will result.
Almost without exception, no matter how benign the reason for locking a thread, we receive at least one, if not several, complaints about having locked the thread. If you want to send me a pm to discuss a locked thread that's fine and if you are polite, I'll be happy to respond and further explain the rational. However, what some have tried to do in the past, and what will not be allowed, is to start a brand new thread discussing why the prior thread was locked.
Such threads will be removed without exception and the original poster will receive a formal warning.