I guess if it happened naturally, "by birds choice", it shouldn't be that bad! The bad/sad part of it is when people do it so that they can sell and make more money out of the rare bird breed, cause as we all see people are no more satisfied with a parrot, they want something that noone has, that talks, that is colourful, doesnt make noise, if possible doesn't poo, its not aggressive etc... The problem is with the health issues that may or may not acure! Natural cross breeding is better then all of those "lab stuff" some people do, for sertain kinds of animals! Many parrots in their "original" breed, born in captivity etc. already struggle with physical and mental problems, cause since the beginning of time we have F it up, but if it hapens under my roof, am i gonna be happy, yes, would i care deeply for them, yes! In nature, cross breeds acure, as a result of changes in environment etc., but is such a slow process that it's not always seen! Some parrots that we now have as a established breed in the wild are results of cross breeding... But of course thats my opinion, and i guess all depends on the reason and situation, i think its not something that can be put toghether, it's more of a many diferent cases, that individually may be a problem or not! I don't know if it makes sence i just tryed to look on the positive side of the story!!!