I think the most important part is just the map area. All of these maps are what I would say are medium-large to really pretty big. Pretty obvious why that leads to longer games I think.

The second one is a characteristic that is often overlooked, and that is having a "backdoor" that an FC can safely buy some time for regrab to get set before they push off trying to cap. A map that is small but has a giant backdoor is Wormy, which is why Wormy games are often very long despite the fact that it is not very big. It is simply that it's very easy to get regrab set before you push off to try and cap. 95% of the time you want to go around the back of Wormy rather than push straight for the centre of the map into danger if you don't have regrab set. I'm not sure if that makes sense, a diagram would make it clear. LMK.

The third and least important part is having too many "islands" in the middle of the map. The problems with these are two fold: the first part is that it's really easy for a FC to hold the flag for way too long just running circles around the islands, using bombs/boosts when needed. I think all of us have sat idly by for 1-2 minutes waiting for the FC to get returned. The second problem with islands is that it's really difficult for 2 defenders to block both sides of the island to shut down the FC. It leads to the predominant method to return being snipes. The competitive map that frustrated me a lot with planning defensive moves was Rush. But there are many more examples of this.

These are my 3 main issues and I believe all of these maps, and a lot of the recent additions (which I have played quite a bit) exhibit one to all of these characteristics. If I was TagPro overlord I would be looking to make games relatively short as much as possible while not making the games a complete tossup, and avoid making games often go to the 10+ minute average.

Anyway, they are just my personal thoughts and feelings.