It is not uncommon at all downtown for bike not to be allowed in the building. I am fortunate that I am allowed to bring my bike in, but I have to use the freight elevator. Normally I lock it up outside just because it is more convenient that getting my bike to the loading dock and waiting on the freight elevator. The only times I have used it is when I have forgotten my lock.
I personally have never had any problems with someone messing with my bike downtown. And if it is locked up right, I don't recall offhand anyone on the board who has.
My suggestion would be to come up with a solution that you could present to building management, dont just go in saying they need to do it. They aren't going to put the energy in to come up with the solution for you, but if presented with a solution that requires very little from them, and wont offend any tenants, then they be more likely to change.