What are these alternatives Picard had at his disposal?
Military victory? That isn't going to happen.
Negotiated peace? That won't work with the Borg.
The Borg never stopped being a massive threat to the Federation, and the entire galaxy, until Janeway "genocidally" infected them with the neurolytic pathogen, killed the Borg Queen, blew up the Unicomplex, and destroyed their Transwarp Network.
Sounds like what Picard had in mind, only taken to another level. Therefore, IMO, Picard should have used his plan, as it was later proven that it was the only workable way to end the Borg threat. Countless people could have been saved from assimilation or death at the hands of the Borg.