Board Thread:Speculation House/@comment-27186569-20170521134631/@comment-3387274-20170606202551

There isn't really any need for there to be a limiting factor. Ethical concerns could be quite sufficent for that, since making living beings and then abandoning them instead of looking after them is very questionable behaviour, and that's aside from filling up the world with what is arguably a new species of sentient life.

although it could just be a unique, difficult to reproduce, experiment in Penny's case, and probably is