it comes down to the fact that WWE believes the fans have the attention span of an autistic 5 year old. this is evident in many other ways. this is why the average RAW/Smackdown match is less than 5 minutes. why most rivalries are rushed, only last a month, an/or end abrubtly (remember Ryback/Rusev just 2 months ago? and everyone thought Ryback was gonna beat Rusev's streak at WM 31? yeah, me niether). it's why the average PPV match is getting shorter and shorter. and why the PPV main events are the only matches that go more than 20 minutes.

Yet another way in which WWE disrespects its fans' intelligence.

I think because of a few reasons:

1) It includes guys that have great metabolism and who won't become too tired or hurt at the beginning of the match. Doing 30 or 60 minute Iron Man Matches includes a lot of energy that maybe most guys can't do

2) It can easily become boring. Fans already complain that matches are boring both on Raw and PPVs. They also complain that other guys don't get enough time. If WWE gave two guys the opportunity of an Iron Man Match, it might end up being boring to fans (even if they are two guys that are talented but may not work well with each other). It may also take time away from more of the mid-card guys that want the chance to shine

Because Iron Man matches require so much cardio to be able to pull off an hour long match, there are very few wrestlers on the roster that can do them

There's apparently been a massive outbreak of ADD in the world, and no one can keep interest up. Butthurt fans complain every 10 minutes the way it is.

The wrestlers would need to have great conditioning & the matches would easily get boring.

Michaels vs Hart, and Rock vs HHH are ironman matches that come off of the top of my head.

Today's sports entertainment fans are patient enough.

They take it after a long time

They take to long

Too much time

VEry long time.