Overwatch: 6 Man, shooter.
LoL: 5 Man MOBA.
Overwatch: A few button use.
LoL: A few button use.
Overwatch: Dynamic Queue Ranked.
LoL: Dynamic Queue Ranked.
Overwatch: Skill Rating based on W/L, Performance on Objectives, ranked from 1-100.
LoL: Rating based on W/L, Bronze 5 to Master Tier (?).
Overwatch Season Rewards: Spray , golden guns (need a certain # of wins).
LoL: Skin, border.
Overwatch: Prioritizing Game.
Lol: Prioritizing Money - skins.
Overwatch: In game coms optional.
LoL: No in game coms (outside client needed).
Overwatch: Premades are made known to both teams at start screen.
LoL: Last I knew, premades were not shown unless you had similar club tags or something. Been awhile since I've played.
Both communities filled with cry babies. I think the last point matters the most.
I presume your original post is getting so much love because people are worried LoL will die for Overwatch. I doubt that'll happen, people always hang onto a game they enjoy. I've quit LoL to play Overwatch, but there are plenty who have not. It's really just how you wanna piss time away.