This seems like a sad example of "we'll do something to children that we'd never accept for ourselves, but it's OK because what can they do about it?"
You might argue against it for babies but at a certain stage feeling the moisture is a motivator for kids to learn to use the toilet.
That's why one potty training technique is to switch kids to regular underwear and mange the fact that they'll be wet pretty frequently. It's the uncomfortable wetness that both makes them want to potty train and lets them understand what it means to hold their bladder.
Wouldn’t they just start pissing literally anywhere, though?
Yes. As an adult male, I piss any and everywhere I can get away with it. Parenting, common decency, and law enforcement have narrowed that down to mostly bathrooms and backcountry.
—First dad joke my brother in law bestowed upon me after my daughter was born
Source: Am new dad of 3.5 year old boy