Speaking exclusively to Sport24 on Thursday, Symcox said he had doubts whether Cricket South Africa's decision to appoint a foreign coach in Ottis Gibson was the right one.
"You appoint a coach and he's got 18 months to create a culture... do a whole lot of things in preparation for the World Cup. And I'm not sure that there's enough time to build a culture in South African cricket 18 months before a World Cup," Symcox said.
"The guy is a total outsider... and we've got a very diverse team... there's religious divides, racial divides, there's English and Afrikaans... it's a very tough thing to unite a team in a very short space of time. At the end of the World Cup, Ottis was saying he now fully realises how important the World Cup was. So maybe we didn't do that job properly..."
Gibson, a former West Indies paceman, was England's bowling coach before taking the South African head coaching job in August 2017.
Symcox continued: "I'm not knocking him as a coach... I know how good he is, I played with him (at Griquas) and was his captain at one stage.
"He was a great bowler and he did all the right things. He's had coaching experience as a bowling coach. But building a culture in a team is a totally different aspect to teaching a guy how to bowl to off-stump on a length."
Prior to the World Cup, the Proteas had placed great emphasis on their fast-bowling arsenal, but encountered problems at the showpiece event in England.
Dale Steyn was injured and never played a game, Anrich Nortje withdrew with injury before the team departed, while there was also ongoing concern over the fitness of Lungi Ngidi.
"I interviewed Faf (du Plessis, SA captain) two months before the World Cup and he clearly was of the opinion that because we dominated with our batting at past World Cups - and it didn't work out - they wanted to go down the road of dominating with their bowling at the World Cup.
"(But) if you go into the World Cup without two of your major bowlers… you're really heading up the creek without a paddle. When you look back at it… was it a realistic expectation for Dale Steyn, who had bowled something like eight overs in two months prior, to come straight into this team and play every single game?" Symcox questioned.
According to Symcox, having a fit squad was imperative as teams could not afford to rest players during the World Cup.
"Let’s face it, at this World Cup there were no passenger teams, every game was critical. It's not like in the old days where we played the United Arab Emirates... Bangladesh in the old days was an easy team to beat… with Sri Lanka you had no problem. I remember in one World Cup we didn't even worry about England.
"But now every team can beat you. There's no game where you can just rest two or three of your fast bowlers and play some backups. Every bowler had to be on top of his game for eight games in a row. We know Ngidi was underdone..."
The team's planning was "clearly a problem" for Symcox.
"When I saw that the backup bowler that came in for Dale Steyn (Beuran Hendricks) was still in South Africa, I asked myself the question: 'Surely you would plan to have your backup bowler, and a backup batsman, playing club cricket in England during the build-up to the World Cup?'.
"So there are little things that point me in a direction that says we made some tactical mistakes on the way into the World Cup. And then, of course, when we got there as well…"
The South African top-order also did not fire, with Faf du Plessis' 100 in the final game against Australia the only three-figure score.
"Hashim (Amla) has been in bad form for two years," Symcox noted.
The former off-spinner added that, while the best available players may have been picked for the World Cup, questions needed to be asked why players coming through the South African domestic system were not performing on the biggest stage.
"At the end of the day, we're pushing out a product that - at the moment - is not competitive in the marketplace. It's not sellable, not good enough.
"The factory that's pushing out the end product is not performing. So you've got to go back to the factory and say 'guys, we've got a problem here'. We're not pushing out the quality to create a product that is No 1 in the world. "
Those problems may lie at domestic level, Symcox hinted.
"The system is a bit weaker and maybe our coaching is not as strong... would any of the domestic coaches be able to walk straight into the national coaching system? I'm not sure that's the case. Maybe Mark Boucher, but for the rest I'm not sure…"
*Pat Symcox also has strong views on the way cricket in South Africa should be administered. In the second part of an exclusive interview - to be published on Friday - he sheds more light. Stay tuned to Sport24.co.za