Apple Maps worked fine for me on day one. It was largely a geographical thing. If there was one mistake in a dense population center, it garnered disproportionate scorn, and all of sudden the whole thing was garbage. It was never that bad when viewed as a whole.
And yeah, that was one of the examples rushing something to market.
As for the iPhone 4, I received mine (from pre-order) a few days before they were technically released, and again, my personal experience was never that bad. I could replicate it, making my bars drop slightly, but it didn’t ruin anything, and they gave me a free case for the trouble. (I am left handed, maybe that made a difference. I don’t know.)
And how about current delays? I say delays are great. Fix it before you sell the products! Better than buying a broken gadget.