That’s the old scoring system. In fact, since at least 1972, amateur boxing judging has always been based solely on “how many ‘effective’ punches did each boxer throw?” - at least that’s how it was supposed to work. (The quick version: whoever threw the most “scoring” punches in a round got 20 points; the other boxer got 20 minus 1/3 of the difference in the punch count.) The problem was, too many judges were using “professional” scoring (e.g. taking things like “ring control” into account), politics, and/or “home country bias” into account. A number of USA boxers got the benefit of the doubt in 1984, but it was probably the Roy Jones Jr. gold medal fight in 1988 that was the last straw.
The revised system had problems of its own - just ask Eric Griffin in 1992, where all five judges scored him as throwing more punches, but because they weren’t “in sync” with each other, he lost in an early round fight.
The new system works like this: in each round, for each boxer, take the five judges’ scores; compare the “low three”, the “middle three”, and the “high three”, and use the ones where the average is closest to whichever of the highest or lowest of the three is farthest away (e.g. for 5,6,10, the average is 7; 7-5=2, and 10-7=3, so the “range” is 3); the average of that set of three numbers is the boxer’s score for that round.
As for using it in professional boxing, that will never happen; among other things, amateur rules do not have the “unwritten rule” where you get a point for a knockdown (e.g. a 10-9 round becomes a 10-8 round). For that matter, it shouldn’t happen; the reason you have the “punch count” rule in amateur boxing is so there’s something resembling a non-arbitrary way to decide the winner.
If you ask me, judging may be bad, but it beats the only viable alternatives: either do what professional wrestling does, and call it a draw if neither fighter is knocked out by the end (but then you get shades of Chavez-Taylor), or have them keep fighting until there’s a winner (“if the fight didn’t go 75 rounds, we demanded our nickel back!” - note that back then, a knockdown ended a round, even if a fighter took a knee intentionally).