It does, although with some speakers that have good vertical dispersion characteristics the exact height won’t be so important.
This is why dispersion matters.
Not everyone wants a sweet spot that's limited to a few centimetres either way. Thankfully sites like ASR, Archimago and Erin's Speaker corner provide plenty of data on this regard.
One thing that has troubled me is when I read that speakers that can sound too sharp can be made more listenable if you angle them away from your ears.
Wouldn’t it be much better if they didn’t sound too sharp in the first place?