But 'Tankie' is not the ideology at all. There is no reason to defend anything which is not the ideology itself. The word Tankie is so meaningless and vague that the only reason to ever use it is if people are actually trying to push on it. In which case you'd first have to ask them what they even mean by the word Tankie because they probably don't know what it means to begin with (nobody really does at this point).
Using it as a self-identifier is self-defeating.