You've just explained European vs American style capitalism.
There are definite "winning" strategies - like acquiring a monopoly on "jail row" and mortgaging all other properties to build it up as soon as possible. But does altering a game so that a child doesn't have to see the optimal moves from someone else do anything positive for anyone playing the game?
I'm going to guess, based on a lot of observation, that most casual Monopoly players of any age don't play strategically. They rely on the dice, negotiate badly (if at all!), buy everything they land on without any master plan in mind, and ignore cash flow until it becomes an issue. These are the opponents most kids will play against in ad hoc games of Monopoly, and in these games, kids will have a grand old time. When the outcome of each dice roll is the most decisive factor in a particular session, a child is at less of a disadvantage.
Also, fwiw, 99% of casual players I've seen overvalue the marquee properties like Boardwalk, etc., and undervalue the oranges, light blues, and reds.
> But does altering a game so that a child doesn't have to see the optimal moves from someone else do anything positive for anyone playing the game?
It didn't, it was a bandage to cover the fact that Monopoly is not a very good kids game.
Now, that doesn't justify turning the game into a 4 hour slog, but it may help to explain why so many people use these "wimp rules".