On the margin, they'll lose some customers, but they'll probably offset that and make money with the increased price. Netflix's customers are generally people who can afford to pay that amount.
Anyway, if you're happy not having any subscription service, it makes sense to drop them. But if you were relying on Blockbuster being a viable alternative, you needed to have done the research first. I'm not aware of anyone who is satisfied with them.
BTW, I fit into that category on the margin, although I dropped it because I didn't have consistent free time to watch movies. I still think the price is more than reasonable if you're able to take advantage of it.