I love parsnips, especially roasted. But I would never mistake them for potato or expect anyone else to either. They certainly have their own distinctive flavour which may be an acquired taste.
They can also be mashed in with carrot and/or potato.
If included in a very savoury stew or soup they might go unnoticed, which is fine if you are trying to include them for those who haven't yet acquired the taste, but a bit of a waste if you do actually love them.