It was setup that way originally, much like the crater map. Both had a very GV center. They have both been changed so much so that we no longer get that GV action in the center of the map. Isles had mounds that you could "use the high ground" in a GV in the center. Crater was so much more GV centric before Greebo redid it. most players were in GVs in the center crater trying to pop tanks as fast as they could before they got popped them selves.
Now, were they changed to get players in the air..... dont know, but they were changed and it did kill the GV action on those two maps.
Well, the map still has bases with GV spawns, they are just airfields now, right? Since there's only one VH, I can definitely see there being an issue with the VH going down easy thus killing the ability to use GVs in the center. A solution for that might be having a GV spawn from each mega field into the center.
I'd argue that the concept of tank town has sort of been long dead, though. I assume most of it was due to dwindling numbers from the days of old, as I spent hundreds if not thousands of hours in tanks and as close air support on the center of ndisles, trinity, bowl, crater, festerMA? any other old maps. There are still plenty of dedicated GVers, but it's not nearly seemingly the 24/7 action there once was. I feel like I recall even when trinity was in rotation, that tank town was dead and that had the 30K mountains to deter folks from trying to bomb GVs.