Whenever you read about breeding Macropodus, you see the comment that they breed easily, so I suppose I should not have been surprised that they did. I didn't expect them to breed in the community tank though - I figured it would have been something that would have required more effort on my part.
It would have been fun to let them breed in the big tank and let the babies fend for themselves. I think I like the platies more because they were able to grow up "by their wits", to survive in what was at the time a much less heavily planted tank. I like seeing a few bold fry emerging from the plants. Raising fry in a dedicated breeding tank is a bit less exciting, although the idea is still appealing. Granted, it's a bit presumptive to talk about raising fry when, thus far, you don't have any clue what you are doing or how you are going to keep them fed.