Lets put some things in an easy to view, and understand, chart (PRO'S VS CON'S).

CLEARLY ONE IS MUCH BETTER THAN THE OTHER.
FIRSTLY kill all the current villagers in towny... ...Villager breeding in towny sounds like one of the worst ideas...
~ @Summers
Agreed. Kill all villagers currently in towny! Then if you want villagers in towny u can buy an egg. Wild world only for breeding and at a reduced breeding rate.
The problem with adding villager eggs is that they'd have to be a very high price for them to not break the economy (more than it already is), but if the price is high than most players won't be able to afford them, thus continuing the monopoly on them
~ @Enron
For 50-100k an egg you will never end someone’s monopoly on villagers.
~ @smk
Thes statements are not 100% factual, "eventually" the eggs will end the monopoly on villagers, it will just take a long time and cost lots of money (money that is removed from the eco so WIN). However, I do agree that the monopoly is very unfair and without any changes, there is no way to even try to overcome it.
I’ll be honest, the chance of getting a librarian or blacksmith from one villager egg is pretty slim, and no one will pay for a villager egg if they’ll get a nimwit that can’t be used at all.
~ @smk
They can be used for "head farming" and that is the "risk" you take when investing in villager trade ( i mean the only other option is to not even have an egg/villager at all, which is how it is currently). I mean don't miss understand, sure turn on breeding I don't give an F. Why?
Because as soon as you turn them on, I will have 1,000+ FOR FREE and so will everyone else (by free I mean not buying eggs and removing money from the eco).