Depending on your character movement/build size it is a bad idea.
Larger characters HAVE to play somewhat defensive, but its still a bad idea because there isn't a decent throw break system to allow them to run damage control in a justifiable manner.
Characters who are faster with movement can avoid being put in a situation where they have to ball up and block everything being tossed at them, so defense becomes a more viable option.
Ultimately its just a broken part of the game system balance. Fortress mode style characters are victims of reset-style characters and don't really have any particular answer for them.
That's a popular thing to say. And its completely true if you have poor pattern recognition, as most fighting game players do. Simply being super aggressive does yield rewards in many cases, safe or not.
but being able to break all throws, that would just make strikes even more risk free. Cause then you wouldn't even get free punish if you blocked an opponents unsafe string.
hmm, make throws unbreakable when they're punish, but make them breakable when they connect on guarding opponents, that actually sounds like a real good idea!