"The first thing that comes out of my mouth has to be ownership and taking responsibility for that performance," said Parsons. "In my personal opinion, we're a better side than what we showed and we should have been able to put the Sunwolves away.
"Also I don't want to take away from the Sunwolves result - I congratulate them and they were a better team on the day.
"The biggest disappointment for me is that I couldn't manage to lead the boys to a performance that I felt was pretty crucial to show our club's growth."
Parsons felt the Sunwolves had simply been more desperate than his Blues, and while their physical preparation for the game was on point, some of his teammates clearly still had plenty to learn about attitude.
"It's a big learning curve for some of our young men," he said. "They need to realise it doesn't matter what team you come up against, if you think you're going to just turn up and play and win, that doesn't happen at this level.
"I hope they learn and never have to experience that again. If there's one silver lining, it's that there is no false sense of security for us, going into 2018, about where we sit and the adjustments we need to make.
"I've always said that our biggest growth area is consistency and the only way we can get that is when our players prepare on a consistent basis to get those consistent results."
Parsons insisted, even though the team had not qualified for Super Rugby playoffs from an ultra-competitive New Zealand conference, they had made great progress to secure a draw with the Chiefs and victory over the Lions in their previous two outings.
"It takes a lot of work to gain respect, but it can be taken away so quickly, and it has been and rightfully so."
Particularly galling was the manner in which the team farewelled stalwart forwards Charlie Faumuina and Steven Luatua, who now take up professional contracts in France and England.
"It's genuinely gutting," said Parsons. "I make no excuses, we needed to be better than that and we weren't.
"That is a real-life example that we can use as leaders, as coaches, of what will happen if you switch off ... we were embarrassed, we still are embarrassed.
"The boys were at the airport, wishing they could fly somewhere else, because we knew what we were coming back to and we knew how much we had let people down.
"We have such loyal fans - there were people at the airport to greet us - and we're so grateful for that support."
Parsons defended Umaga against calls for his head after a disastrous end to his second season in charge.
"I've had so many coaches over my career and, unfortunately I feel like the same problems are still there, so I don't think everything can fall to the coaches.
"It's an easy fix, because it's one man to get rid of, but I have full belief in Tana. We clearly have to make some changes - we're just not getting the results - but he is a passionate Blues man and he's in that building 24/7, trying to make us better.
"The first thing he said to us after the game was he apologised for not being good enough to get us ready for this week.
"He takes ownership and is a man about it, and I think that's a great man to follow."