Best speaker/system piano concerts

Underpowering any speaker can ruin it.

FWIW dept: the result being a fried tweeter.

Any kind of music including piano can damage a speaker if the speaker is abused in some way. I wouldn't blame that on rock.

Any speaker that is free of artifacts and has enough power behind it will do the job. You can't build a speaker that favors a certain instrument- that is like making a speaker that favors a certain kind of musical taste. Speakers don't care about that, they are a collection of parts that make sound and can't express taste on their own. This however is the most persistent speaker myth in the world.
IOW a speaker that is really good at piano will be really good at black metal, jazz, classical and Chinese pipa.

To reproduce pianos, like an orchestra or modern rock band, you need to make sound pressure without distortion or coloration; there needs to be enough clean power driving the speaker to do the job. If your electronics have issues, a good speaker will simply reveal that. IOW you need a good amp too, and amps don't have any taste either.