Why rectangle lights were not implemented?

I remember from my old days at engineering career that we made lots of flux related problems, and I know that when surfaces get into the game the problem is much more complex than when you use only ‘points’, but I cannot imagine why cylinder lights are supported and planes are not. Maybe I’m wrong but I think that complexity on both kind of lights should be more or less similar.

I could spend some time adding support by myself it is easy but maybe someone can give me a reason that illustrates why that’s more complex and it will save my time.