Morgan's current pacifist philosophy is as insane and way more dangerous to others as his former "Clear" insanity. In his 'Clear" insanity the only ones he put in harms way were those he himself shot at. Now he is literally responsible for if not every Alexandrian death, then certainly most of them and a unknown number of other victims the wolves have taken and walkerized that we are not aware of.. If he had killed the two 'breakfast' wolves, they would not have killed the poncho guy, They would not have found Ricks map, (other wolves might have though) but for sure these two would not have. And the people killed by these two would not be dead by their hand. And correctly Rick would not have been attacked by the wolf with the gun he stole from Alexandria in the Rv, although the others might still have taken knives to a known gun fight with Rick. So Morgans' incredibly selfish and arrogant self serving philosophy is responsible for if not all then certainly most of the lives lost that we know of so far, Including Glenns' if he is indeed, dead.
IMO, Morgan is no more responsible for the fate of the Alexandrians that the Wolves slaughtered than Aaron is. The Wolves made their own choices. If Morgan could have seen into the future what the two Wolves that he didn't kill would do, then he would bear some responsibility. As well blame Rick for taking most of the fighters away and leaving the community vulnerable.
On a practical level, it seems to me that what Morgan did made no difference in the end. The Wolves were out there ranging around and had already moved north from Noah's home towards Alexandria. Walkers that they had made, marked with the W, were already to be found within walking distance of the community. It was only a matter of time.
All that being said, I disagree with Morgan's refusal to kill anybody at all. In their world, sometimes, they have to. But I do think that Morgan and Rick can learn from each other: sometimes they have to kill but they don't have to kill all the time. Right now, both are too extreme.
I mean, isn't that what JSS was partly about, with Carol as Rick's proxy in this debate?