On pestering: You'll note that almost none of the top bullet makers offered .20 caliber bullets until the 204 Ruger came out, even though there were/are many wildcats based on that caliber. Nosler waited until at least three other makers were getting all the market share on them, then once they saw the twenties were taking off, they jumped in all the way.
Sierra is about the same, not wanting to tool up and suffer all the associated costs with doing so if they would suffer lackluster sales. Now that the 17FB has been added to the commercial 17 caliber list, I'd think with some more pestering, they'll see that the 17's as with the 20's, have a very large following, and they'll relent and tool up.
All of this shows another side of the sport; the small calibers are more fun to shoot, less expensive when compared to the large boomers, and have a very large following.....
us! 
Remember the old adage: "The squeaky wheel gets the grease".......