While I don't agree that you should be rewarded for NOT doing a fame grind...or making the sacrifices that comes with aligning with a race or faction, I would support this idea if you made the titles require a certain fame.
For instance, your hominist titles could be available to those who have various levels of fame with ALL civs.
Hominist :: 1 Fame with all civs
Peacemaker :: 30 Fame with all civs
Mahatma :: 50 Fame with all civs
"Diplomat" has the connotation of being aligned with a civ, but working with another. Maybe x amount of Fame with a civ you are not aligned with...while being aligned with a civ.
For instance, your hominist titles could be available to those who have various levels of fame with ALL civs.
Hominist :: 1 Fame with all civs
Peacemaker :: 30 Fame with all civs
Mahatma :: 50 Fame with all civs
"Diplomat" has the connotation of being aligned with a civ, but working with another. Maybe x amount of Fame with a civ you are not aligned with...while being aligned with a civ.