Why is the dipole moment of acetone higher than ethanol?
Dipole moment is just one of aspects of solvent polarity, as is well known in HPLC separation  analytical technique where the following effects take part:

Dipole moment interaction, permanent and induced
The above for the whole molecule and for particular bonds
Electron pair donor
Electron pair acceptor (including $\ce{H+}$ donation)    

Depending on solute molecules specifics, the solvent polarity order is variable, as various molecules have different responses to above interactions.

See also Using solvent triangle in HPLC