Well, it's all in how you want to look at it. Two of those teams have only been around since the mid 90s and two others came into being after KC won their first and only...and the Jests had theirs only a year before the Chiefs managed it, so it's not that great a distinction.The following 13 teams have never won a Super Bowl, and the N.Y. Jets won their Super Bowl before the Chiefs won theirs in 1970.
1) Houston Texans
2) Jacksonville Jaguars
3) Detroit Lions
4) Cleveland Browns
5) Minnesota Vikings
6) Buffalo Bills
7) Cincinnati Bengals
8) Philadelphia Eagles
9) San Diego Chargers
10) Atlanta Falcons
11) Tennessee Titans
12) Carolina Panthers
13) Arizona Cardinals
IOW, the Chiefs have a more recent Super Bowl victory, or Super Bowl victory period, than almost half the teams in the NFL (44% of them)
So KC can crow over about 9 of those teams with some legitimacy. And two of those went to four SBs apiece, which isn't hay, potentially shrinking that distinction to 7 teams who didn't fare as well. A couple more of those are old teams in name only.
Essentially, to boil it down into laymen's terms, the Chiefs stink on ice...or they have, but I hope those days are behind them.