No football authority could ban a player for life for such an act as football is their livelihood and you cant deprive a person a chance to earn a living.
A decision of "ban for life" would be taken to a "proper" court and probably overturned, thus setting a precedent for all future "bans" to be challenged in the court.
The football authorities are scared stiff of any decision they make being taken to a proper court as once it is overturned it diminishes their authority and makes it harder for them in future to uphold bans.
btw. I would hardly say a 10 game ban is trivial, it is a quarter of a season and he wont play for 5 months (with the summer break).
I am not condoning what Suarez did, and I agree with you that football players have been getting away with some awful behaviour on the pitch for year.
I would like so see any player who "harangues" the ref sent off, and we may get more respect for refs like we get in Rugby.
p.s. One quote I heard years ago was "Rugby is a game for thugs played by gentlemen, and football is a game for gentlemen played by thugs".