I am sure many of you have the same problem. The shampoo and shower gel bottles don’t all fit on the minuscule shelf that the shower head rail came with, and you dare not put too much weight on the little baskets with suction cups, so they go on the shower floor. Depending which brand you buy, you may have a problem with water from the shower getting into the bottles and diluting the contents.
How much effort would it really be to design the caps so they always spring back to cover the hole when released? The only minor technical difficulty would be that you need to get the stuff out on to one hand while holding the bottle in the other, so you don’t have a hand free to hold the cap open, so it must stay open while you are holding the bottle. A simple cantilever would work fine, or using plastic that springs back only slowly, so you have a few seconds to squirt some stuff out.