You really can't help yourself, can you? - you've always got to disprove the other guy and defend your statement even when you've been called out. And you always fail.
Saddle up.
Even if you take the average of all of those running times over the course of the day, the average frequency of the NYC is 7 minutes and 22 seconds across its operating day. The 5 minutes quoted run time during peak hours is also smack bang in the middle of your quoted Superman dispatch times.
However you should be careful of your sources. The site google has quoted there is not an official site - but a tourist blog run by a commercial tour company - Civitatis Tours.
Let's check some other sources:
Wikipedia starts off noting there are actually five different service patterns, rather than the three the tour company mentioned (the others are late night and weekends, so presumably won't help bump the average). What's also notable is the fact the NYC Subway has 28 different routes, and each operates different frequencies - expresses, all stops, some only in non peak times - but what gets really interesting is this table:
What we see here is that, even in rush hour, not every train comes every 2 minutes, and if you average it out (based on the fastest time for each line), it still comes to 5 minutes and 40 seconds during peak.
Now, assuming we take wiki with a grain of salt:
The official MTA website shows all the schedules for every line, and if you go and look at those examples during peak hour the frequency is scheduled quite often less (ie, longer wait) than posted even in Wiki.
Pedestrian Observations has written an article specifically regarding the NYC Subway frequency, and in their own analysis, they found an average of 5 minutes and 42 seconds during morning peak across all lines.
New York City Photo Safari (another tourist blog) states most trains run every 7-10 minutes, with some as many as 15. It notes that if you wait more than 10 or 12 minutes, it's unlikely the line is operating at that time.
TL:DR - you got owned, stop talking out your arse and just accept the L occasionally.