This would amount to reducing the average lot sizes by 1/3. On the one hand, the notion that this is "unrealistic" is kind of funny. On the other hand, I don't really think it addresses an actual issue that homebuyers have; once you have to maintain a yard and the exterior of a house, how much less work/expense does a 1/3 smaller lot get you? Do people actually object to having a bigger yard that looks like you could play catch in it?

I'm well aware of the problems with large lot zoning, but I don't see how a change of this limited magnitude would "meet the needs" of anybody whose needs aren't being met now, except maybe land costs being a bit lower.