Think of recessive as "being PURE for the GENE" to show it.
Therefore all silky feathered birds are pure for the recessive silky feathering.
Your bird, having normal feathers is not "pure" for the silky feathering gene. This is the reason for answers above saying they are not pure, and they are correct. You got the eggs from someone... how do you know for sure a smooth bird was not a parent?
For example.. if you cross a silkie with a cochin, you get birds feathered like a cochin(but it can look or feel a little softer). That is because the cochin does not have the silky feather gene.. the cross babies carry the silky feather gene but since they are not 'pure' for it, they cannot have the silky feathers.
Now if you breed the silkie-cochin cross birds to a silkie, you will get half smooth feather and half silky feather. That is what you are seeing with your birds. As long as you breed a smooth, you will continue to get some smooth, some silky. Only when you breed silky to silky, there will be 100% silky babies.
As for to keep or cull, that is completely up to you. if you like it, that's all the reason you need to continue breeding them. If you don't like it then that is also a perfectly valid reason to cull.
Edited by Kev - 2/6/16 at 12:53pm