No, they don't want it badly enough, so they won't get it. Not that they don't deserve to get it.

I find this line of reasoning unconvincing since I take the passage as a whole to be intended to make people okay with brick walls.

Why do you believe this?

1)

I heard the whole speech last year sometime and concluded it was largely prescriptive at the time.

Ah here we go:

But remember: The brick walls are there for a reason. The brick walls are not there to keep us out; the brick walls are there to give us a chance to show how badly we want something. The brick walls are there to stop the people who don't want it badly enough. They are there to stop the other people.

http://youtu.be/ji5_MqicxSo?t=17m47s

2)

I suppose you might view it as an attempt to make people rail against the injustice of everything. However I believe that learned helplessness is a huge thing in our society and that strategy doesn't plausibly fit into how I imagine most people as being likely to behave if you tell them something's terribly unjust.