stabbing sideways would generate little to no power. you are relying on your upperbody only, instead of horses interia
a 80° frontal arc for thrusting is very realistic and makes sense game wise. Now if they would change it so couch lances and lance thrusts would really outrange stuff like 2h swords (long/bastards) this would be great.
As it stands, frontal attack on 50% of the playerbase is suicide. Only people you can safely attack are shielders that dont have 1h sword