A grab bar is a structural fitting. A towel rail is convenience hardware. They look identical from the room side. The difference is behind the wall. A grab bar is fixed into framing — a stud or blocking — so it can carry load. A towel rail is fixed into drywall with an anchor and is designed for light loads only. If someone puts weight on a towel rail, it can fail. A grab bar is designed to be grabbed and pulled and to support a person's weight.
Where a bar is reached for is not a designer's choice. It is described by the movement of the person using the shower. Getting into the shower, they reach for something to steady themselves as they step into the tub or the shower base. Turning in the shower, they reach for a rail to maintain balance. Getting out, they reach for a bar to help pull themselves up. These are the movements. The bars go where the hands naturally reach during these movements, not where they look symmetric or balanced.
The load path into framing is the critical structural detail. The bar takes load — sometimes very high load, sometimes someone's full weight. The load goes through the bar into the bracket, through the bracket into the wall, and into the framing behind the wall. If the framing is not there, the load has nowhere to go and the bar fails. This is why blocking for grab bars is installed during framing, when the wall is open.
Putting blocking in now for bars fitted later is the cheapest decision available at the open-wall stage. Blocking costs little when the wall is open. Installing it later means opening the wall again. Specifying blocking locations during framing means that a future grab bar installation is a simple task of adding the bar and bracket to existing blocking. Without it, the wall has to be opened.
Bars that do not read as institutional are bars with the right finish and form. A brushed nickel bar looks different from a chrome bar. A bar with a subtle profile looks different from one with heavy geometry. The structural requirement is fixed — the bar has to carry load into framing. The finish and form are flexible. A well-designed grab bar looks like it belongs in the bathroom, not like medical equipment.