I started commuting on a hard tail MTB years ago, and switched out the suspension fork for a rigid fork after a while. Honestly, weight and clunky appearance never crossed my mind, at issue for me was the rigidity. I was very glad with the change, particularly on a few spots where I would stand up and pedal and no longer felt so much energy going into the shock.

Watch the axle-to-crown height. You can get rigid forks (sometimes called "suspension-corrected" or similar) that are made to set up pretty well with frames that were designed for the taller suspension forks. Droy45 is right in his post that the geometry can be an issue, but you can get past that with the right rigid fork, they are not all shorter.