"How the fuck can they allow full sized Zentradi on a colony ship like that?
Its a fucking waste of resorces when they could be micro."
It's their choice to live full-sized. It isn't any more a waste of resources as inviting a Superstar from another Colony ship to have an expensive concert. Hell, even the icecream stands and cable cars are not strictly necessary either.
The Macross universe has expanded technologically way beyond the typical setting of everyone living like monks just because they are on a ship. The colony ship is filled with luxuries because it isn't for refugees, but immigrants who have to be CONVINCED to get on board. These immigrants might spend the rest of their lives on Frontier, so it is unreasonable to not give them the luxuries they want.
If someone want to live as a giant, and have the means to support the lifestyle, it's their own damn business. They are paying for the resources out of their own pockets after all.