There is no one reason really. It can be for many.
Dev blogs show things that are still in development. Even at the point of a blog, things can still not be final and subject to change. A serious issue or error may pop up that prevents it from being shown or a number of other reasons.
It seems fair to me. Then we decide if we play or not.
Starting a nation from 0 to obtain high-level vehicles involves spending money on premium vehicles, premium accounts, crews, crew points, talismans, etc. It seems fair to know what I’m spending my money on, this is not a garage sale.
There may be people who think differently, that’s a fact. I think this way.