I agree, if it is a noise or practice space situation, then electronic drums certainly fill the void when you can't practice on an acoustic kit.
What I meant by replacement for acoustic is where I think the electronic drums argument falls apart, if you will. In a live setting, I approach electronic drums in a way that they are not making acoustic sounds, but processed sounds or even not drum sounds at all, maybe samples of other sounds. That is where I think electronic drums could and do really shine.
But making them look like acoustic drums for sometimes quadruple the price is not necessary to me.