No, no I mean actually did it because they thought that would be the correct answer and then were forced to restart because surprise! "break up". At the point i was making the decision i didn't even thought it was a possibility.
The argument you make, make perfect sense and I have opinion too on this (and for me it is a bad idea too, and it has to do more with him making a choice than the lyrium actually)
Zero probability does not exist. There will always be people who told him back to lyrium & not realizing they'll get dumped afterward. Or choose "we'll find safer way later" & does not realize that it's also possible to encourage him to stay on his initial decision.
I think for most people the breakup was expected. He's going through a horrendous time and in his mind lyrium=work is more important/performance is more important than passions and such?
I don't really get what you want to say actually, can you please explain a bit more?
I think that he tried to do both at the same time, being a good Commander & tackle his personal issue. That might be why he works so hard (one of the question we got to ask him when arriving at Skyhold was "Do you ever sleep" to which he responded things like "too many works to do" or something like that). But then he reaches his breaking point & feels unable to do both at the same time & afraid of being a liability. Which results in him talking to Cass...
I get a friend of mine (a guy who is uninterested in romancing him & don't like him in general but don't dislike him either) who told him back to Lyrium because he feels that Cullen had accepted the responsability of being a Commander of the Inquisition Army then he must assume this at all cost (including him back to Lyrium for better performance).
I mean, all the Perseverance quest when we're encouraging him to stay on his decision to stop lyrium is basically telling him "I'm okay if you want to do this, I can tolerate you not being as good as you could have been as a Commander if you're leashed back to lyrium." I honestly feel that just because we're in game that we can hardly see the difference of his "work performance" as a General.