When we first started visiting Thailand, we found that some hotels (even 4 star) didn't provide tea and coffee making facilities. Whether this is to make guests use room service/coffee shop or whether there's some other reason I don't know, but it's annoying just the same.

Even though we now usually stay in a serviced apartment when in Bangkok, we usually head off to some other location and so we take the kettle, just in case!
Ours is steel but I've seen plastic/melamine ones in Tokyu homewares section.
There have been many times when we've been really glad we've had this kettle with us.