Except it's not a big deal. At all. In the end you're still riding a horse with full opportunity to view the beautiful world around you. Is having to bear watching your horse gallop really that much of a problem? And besides, the IMMERSHUNZ excuse is being thrown around so much it's losing whatever meaning it ever had. See sig.
The word is used once by the OP and then the 2nd person to bring up the word is you. There is nothing wrong with watching a horse gallop all by itself, it's when you are anchored to it yet you see it far from a distance then it becomes a problem. Anything that distances you from the character is bad. It is not the main aspiration of a good RPG to immerse the player in the world but I'd argue it is the 2nd highest priority of an RPG being closely tied to its main priority, so things that strike the player as a reminder that they are not taking a step forward when they press W but that they are commanding a character like a puppet on strings to take a step forward, are bad things for the game.
Yes I realize some people are throwing the word "immersion" around too much however that does not mean it can't be used within proper context. It can also get a little annoying when people start to bash on people with legit concerns about the atmosphere of the game and how well a player can immerse him or herself within its setting, using the term "IMMERSHUNZ".