I can confirm this is common. But after sterilizing the bottle or washing the bottle, you don't give that water to the child. One usually just cleans using the microwave, rinse it out, then you add water from another source that hasn't been in the microwave in a plastic container.
Well yes, but whatever milk/water you serve in it right afterwards will still taste and smell of burnt plastic. I take it as something inevitable because no one's going to be giving a glass milk bottle to an infant.
Maybe I should dump every single child plastic drink/dinnerware for 18/10 stainless steel.