I'd love to delve further into this, as I've heard the sentiment from a number of players, and to me it just sounds like another "I hate pineapple on pizza" comment, so let's ask a few questions to try and determine what the route cause is, here's two easy questions.
Is it because of the HD-Nature of the skin?
Or because there's shaped models on the minecraft blocky body?
In the case of #1, HD-Models have always existed. MPM (More-Player-Models) was commonly used since the dawn of the server.
In the case of #2, Mods in the MC scene have added existing 3D models to the game, does that make them 'Roblox'-y?
I'd love where this opinion stems from so we can sort out a route cause to attempt to make time more enjoyable.