There is no obligation to purchase a SMF premier membership. It gives you a few perks and it helps me pay for the site along with the recipes but the free memberships are still there and will remain that way.
I have been asked a number of times to provide an "enhanced" membership option and this is in response to that.
It gives folks a way to support the forum.. it is definitely not a status symbol by any means.
Most forums of this size offer this option and I tend to think it's a great idea.