It's a question of taste, I suppose. I don't use acrylic, and didn't when my children were babies - I quite enjoyed washing tiny hand knits in Lux flakes.
I don't like knitting with acrylic, it has no memory, isn't anywhere near as warm as natural fibres, and as has been said, it's basically plastic, so it's definitely not perfect for me.
I understand that it's washable, but so is superwash wool, and there are other alternatives, as we've seen on the thread. That doesn't mean that those who do like acrylic shouldn't use it though - there's a lot of choice, and if there is any risk of the recipient spoiling a painstakingly knitted item by tumble drying it, it makes sense to use it.