To be fair I don't agree with that either (oh contrary me). It's important to see someone who knows what they are doing even at basic levels. They need to know what you are interested in and how to keep it safe without losing control. You should discuss a safe word and also what you would not be happy with, so boundaries are kept. Personally I have a check list that allows a 0 to 5 rating of each activity, so I have at my finger tips what the client is confident with, enjoys and what they would never touch with a barge pole.
An amateur could easily cross boundaries through ignorance, so never a good option.