I agree... but not in the way the Twitter OP expects.
For the majority of intersections, if you don't press the button (or more often, don't press it in time), you don't get the walk light. Doesn't matter if the parallel car traffic has a green and all cross traffic is blocked, if you didn't press it beforehand, it stays on the red hand and skips your turn.
I say the buttons should not be there to "beg" for crossing permission. They should be used to say, "Hey I'm in a wheelchair or carrying a heavy can you give me 15 extra seconds?" And it should not need to be pressed beforehand.