St Kilda tagger Baker received a nine-match ban for three charges of striking and one of misconduct after his attempts to distract the Geelong forward in their round-13 clash.
O'Keefe, who has moved into the Swans' midfield in the past 18 months, applauded the decision of the match review panel and the tribunal in outing Baker for the rest of the premiership season.
"If you look at most decisions that get made in any sport, really, there has to be a critical point that changes everyone's thinking," he said.
"Obviously it's been brewing for a little while and this has happened which has made the change. It's better late than never."
The Swans midfielder, who will bring up his 200th game against Richmond at the MCG on Sunday, hoped the ruling would lead to a new era of fair play.
"That sort of stuff in the game, you can't tolerate and you [must] protect the ball players. If you're going to be a good player, you shouldn't have to fear someone just belting you all day," he said on Wednesday.
"I think the AFL's made the correct decision and I think we've got to stamp that out."
O'Keefe said he had never received attention from an opponent that he considered "dirty or untoward" but he understood the frustration that led to Johnson lashing out with an elbow that caught Baker in the eye.
"Very much so. There's been many times where you'd just like to let go, but it's something where you just have to have a bit of mental strength," he said.
While Baker's hefty ban will no doubt serve as a deterrent to other taggers considering similar gamesmanship, O'Keefe said the umpires still needed to monitor fiery contests on the field.
"I think it could be done even sooner. If you pay a couple of free kicks early against those guys, then they'll stop doing it. But I think it's in the right direction, what the AFL's doing," he said.
