In this household, towels are weekly and the bathroom floor rugs are usually included, along with the kitchen towels. Otherwise, the machine wouldn't even make 1/4 full (this load is typically 1/2 full), and because there isn't a lot of space for "dirty laundry" the way our house is setup (and/or it wouldn't be pleasant to see).
This wash gets run in the Miele on the standard Cottons cycle, with Water Plus selected (More water/extra rinse, for 3 rinses) and sometimes a Pre-Wash. Main-Wash is at 60ºC (140ºF). Prewash will typically run at about 40ºC (104ºF).
Machine is presently running the "Euro Programming" mode - so the cottons cycle can/will tip 3hrs on this load.
No-one here has been sick, and towels don't smell musty in between washes. If they do, they go onto the clotheslines outside, and then either into the wash hamper (and replaced), or are used again - I mean seriously, if UV kills bacteria and they're dry, what do I have to worry about?
Usually, the weather here is dry enough for towels to dry completely between uses. So there usually isn't any need to replace them often. In all fairness, if you are "clean" coming out the shower, why replace the towels daily?*
*Alright, I'll admit I'm more OCD about my own laundry - and do go to the extent of separating darks/lights and underwear/socks, but that is more for the sake of the different temperatures I use (and "caring" for fabrics in this manner).