Lucrative cargo?
Certainly not on the North-Atlantic, and on many other destinations that are popular with passengers the cargo yield is on the very low side. Check how many cargo carriers fly freighters beween London and JFK and it will give you a hint of how 'profitable' cargo is on such a high frequency route.
Some people suggested a legislation for minimum seat pitch. Well, you may be surprised, there were regulations around for quite some time. Remember that the tourist (nowadays called economy) class did not exisst until the first jets appeared on the horizon, and the pitch of that class was limited to a minimum of 34 inches (except charter airlines). Only after hard public outcry did this change to the now (actually regulated) minimum 28 inches on a so-called high density pitch seat.