OK I'll accept that you were not calling me unprofessional. But I do not believe reading the oath off a card is any less professional than memorizing it. It's a matter of preference.
I'll give you an analogy here. Emergency procedures. If you ever look at an original DC-10 flight manual, you will find a large number of bold face EPs that the FAA thought every pilot should memorize. Through the years the number of bold faced EPs got less and less until when I did my last check ride at Hawaiian there was only one left (O2 masks on for rapid decompression). There are many pilots that think it is more professional to memorize all the original EPs yet the FAA has done many studies that show those who run EPs from memory are more likely to do them incorrectly. So the FAA has reduced bold face EPs to the bare minimum. So what is more professional? EPs from memory or EPs from a checklist? Neither - an FAA examiner or a Hawaiian check airman would accept either. Completing the EP correctly is the professional thing.
Same principal. If you read the reenlistment oath you are more likely to get it correct than if you try it from memory. In my mind, getting it correct is more professional. If it takes reading it from a card to ensure it is completed correctly, then reading from a card is more professional.
