As a long time FPS player i actually find the lack of movement accel in Overwatch to be a really good change for FPS games. You can argue that accel/air strafing adds another dimension of skill to the genre but the mechanics are so subtle most players let alone eSports spectators will never ever notice how important it is. It's fucking retarded to lose duels in an FPS if you have equal or better aim and gamesense simply because your opponent can stafe jump to the pickups better in Quake or reset their recoil/movement spread faster in CS:GO.
That is a disadvantage you cannot willfully overcome without putting more time in the game; there is no other alternative. It wouldn't be an issue if most popular FPS games in the genre didn't have incredibly specific movement mechanics that barely transfer well between each other adding artificial difficulty to each separate title.
MOBA mechanics aside Overwatch plays like an incredibly clean and straightforward FPS title which I find hard to criticize.