I dare you to take a look at your shower walls. All that tile, all that grout with mold and mildew growing on it. Fiberglass walls with pink gunk inhabiting the spaces where the parts meet. Bathrooms are damp moisture laden places, mold and mildew love damp moisture laden places. Ergo, bathrooms are breeding grounds for mold and mildew. What? You really expect me to sit in that? Hell no!
Stop to think about this, we scrub the tub, but do we really scrub the walls each time? We wipe the walls or use those useless against mold and mildew scrubbing bubbles. Even with those new shower spray cleaners there is still a build up of mold spores. Try not washing the walls of your shower for a month. I dare you. See what you will see, and mark my words, it ain't pretty. Pink and black slime grows there. Honest.
I never saw a shower until I was 8 years old. Baths were taken once a week and we washed all over daily. Sometimes twice a day. It wasn't until we moved into the house that Dad built, that showers could be had. I remember my first one, I hated getting water in my face. When given a choice between shower and bath on Saturday night, I'd choose bath. Now, I can't sit in a bathtub, I feel icky sitting in my own dirt. Can't convince me otherwise. My mind suggests that there's yucky stuff floating in there with me. Who cares that todays water is filtered and chlorinated? Who cares that daily showers clean much better than those "spit baths" that we used to take when I was a kid? There's icky, yucky stuff in my bath water, that's all there is to it.