Rather than there not ever being a jon-skeet tag, it seems from the comment by @Glorfindel that:
it has been created quite often and then it gets deleted by regulars (read: the regulars remove it from all questions and then it gets deleted by the system as an unused tag).
ItThis indicates that the reason there is not a jon-skeet tag is that the community sees no case for its existence and burninates it whenever it is re-created.
Rather than creating it or repeated burnination it seems to me like blacklistingblacklisting it may be more appropriate, to prevent each new cleanup (burnination) being needed.