Steiner was outspoken ahead of the Spanish Grand Prix in expressing his annoyance about why Nico Hulkenberg was handed a penalty for an opening-lap collision at the Monaco Grand Prix.
He thinks it was unfair for Hulkenberg to be sanctioned for what he felt was a non-incident, when other drivers had got away with much worse.
"Lap one: we get a penalty for what I think is not a collision," said Steiner. "There are other people running into each other during the race - they get the black and white flag. So, I think it's very inconsistent.
"Then we look at the accident in Miami between [Nyck] de Vries and [Lando] Norris, in lap one, that was no collision."
Steiner went on to claim that an ongoing lack of consistency in stewards' decisions had left him feeling the time had come for professionals to be brought in.
"Every professional sport has got professionals being referees and stuff like this," he said.
"F1 is one of the biggest sports in the world, and we still have laymen deciding on the fate of people who invest millions in their careers. And it's always a discussion because there's no consistency.
"I think we need to step it up. I think it's now time. I think we're discussing this for years and years and we always go back to this."
Source: Autosport