Even Mo’s “peaceful” Mecca-era rants are clearly self-interested; the only difference is that his interests changed over time as he accumulated power, wealth, and access to sex.
The tribal basics. Money sex power plus polygamy give unmarried men strong incentives to become warriors, to join Mo' army to to find an infidel female sex partner/sex slave/wife all rolled into one or forget the wife part. Same as American Indian tribes were very keen on grabbing their enemies women via war. To turn into sex slaves and wives. For their own pleasure and to crank out more warriors. The larger the tribe the better its chances to win wars.