Excellent question! It is very frustrating to negotiate with an agent that can not return your call until after 5pm or later because they are at a job they can not respond to you or the agent is not able to understand logistics of contracts, mortgages, appraisals, home inspections issues, well test, COs, BPO, Bank owned properties, ect..... In todays market, buyers and sellers want timely accurate information. waiting for answers could make or break a transaction. I do agree with Laura, often times it is a friend or relative. A new agent deserves the opportunity to get into the market, but they should be willing to be accessilbe and get the answers requested.
If the buyer and seller are aware they are part time and agree to be represented by the part time agent it is thier decision. I recommend the part time agent pari up with a full time agent that can handle issues as they arise. But we do not live in a perfect world. Even full time agents do not communicate on a timely basis.
I too was part time when I started 22 years ago, until I had enough listing and sales under my belt, so on the other hand I get it. That is the luxury of this business.