The Vikings didn't have that issue in '98, but they did have plenty of holes on defense, and easily could have drafted defense with their 1st pick.
But I agree, the Vikes were pretty decimated at CB going into last year's draft, so they probably wouldn't have taken JJ with having just one pick, unless they REALLY liked him, and thought Diggs was a little unhappy, and didn't think they could trade Diggs at the time.
I am sympathetic to your point because I am a best player available guy.
Here's a tweet from Dustin Baker (unrelated topic):
Offensive TDs Scored,
Kansas City Chiefs = 54
Minnesota Vikings = 55
We live in a world where we depend upon each other. In other words, we need each other just as God needs us and we need Him. How wonderful it would be if we could unite and live in harmony. Wouldn't it be better that way?