OP is kinda right. Most players are just too inexperienced to realize it.
I don't agree with the Assault Rifle comparison at all. However, it is pretty much fact that a lot of Marksman Rifles are better than all Sniper Rifles in every possible way. At least in hardcore which is what I play the most. I have tried a lot of both gun types and Marksman allows you to shoot 4-5 times very quickly AND very precisely with more than decent zoom while the sniper only shoots one bullet and needs to hold breath. With a Marksman Rifle I have no problem one shotting a guy across the map in Stonehaven Castle for example, one of the biggest maps.
More and more players will realize this as they get to my level. In the mean time, let the noobs think we are crazy and let them think snipers are OP lol. We know the truth that's why we are better players.