Thats why I said a mount can be as wide as 36" for a 58" tv (which would be about 49" - 50" wide). The mount could be anywhere from 1 to 3 feet smaller than the tv itself.

It is in this case because the tv itself is 58", which means it can be used on a mount that is up to 3 feet wide. So that is why it's hard to believe that there are no 2 studs within that range.

How wide are your studs that a 58" tv cant be mounted across two? That tv is just over 4 feet wide, and mounts can usually be up to 3 feet or so, for that size tv.