The simple answer is, porcelain is fairly durable, nonreactive and, well, smooth. You don’t want a material that’s prone to sticking in any way. The shape needs to be a certain way for the water to do away with… things, and not go everywhere.
That sucks when you have one of the THBPLTPLTBPHLTHLPTHPLTPPL ones in company, though.
(A rusty one?)
The simple answer is, porcelain is fairly durable, nonreactive and, well, smooth. You don’t want a material that’s prone to sticking in any way. The shape needs to be a certain way for the water to do away with… things, and not go everywhere.
That sucks when you have one of the THBPLTPLTBPHLTHLPTHPLTPPL ones in company, though.
It also needs to be cheaply mass producible. So making stuff from literal dirt is a pretty smart idea.