The 55-year-old, appointed by former Aberdeen team-mate Gordon Strachan last week after he took over as national boss, was most recently manager at English fourth-tier side Bristol Rovers before being sacked last month, which followed a torrid spell in charge of the Dons.
McGhee was interviewed for the top job in 2008 before George Burley was appointed. "I see those two episodes (at Aberdeen and Bristol Rovers) as failures as well, therefore as far as I am concerned I would imagine that people would be questioning my ability, my motivation to still be doing the job," he said at a Hampden Park press conference.
He added: "So yes, I think I have questions to answer and I think I can only do that below the surface. I am not the manager, I am not there as the number one, all I can do is give Gordon as much support and make him the best manager I possibly can and hope that people see the job I'm doing and appreciate it.
"I have enjoyed Christmas at home and my intention was to be a football manager or coach. I am not going to sit here and go into what happened at Aberdeen and Bristol Rovers, but I feel I have a legitimate right to consider myself as a viable football manager."
McGhee, however, saw no reason for having to justify his appointment.
"You only have to look at the nature of our business," he said. "I am not the only manager who has lost his job and got another job, that's what happens.
"Anyone who looks closely at circumstances and situations in any football job, will know that there are more than one side to every argument. People get sacked and get jobs again.
"What you have to do is not be blase about that and expect that every time you get the sack you are going to get another job. I think you have to be determined and I feel very unfulfilled as a manager, regardless of the successes that I have had, and I have had a lot of successes.
"But I feel very unfulfilled as a manager. I imagined that I would spend my whole life managing in the Premier League and I haven't so I still have things to do and getting an opportunity at this level is okay."