I don't mean for midwar shananigans to be taken as an insult, especially since I've done the same thing and enjoyed it.
Funny how the game changes with changes in tactics, just like tactics change when the game changes. The way I see it as far as base closing goes is like this.
When I was new to the game it was all NOE all the time, lots of 110s flying below radar was pretty much the standard and an easy route to success.
Then the towns and fields got a bit more complex. Before we had the flag and it took 100% of buildings down to get a capture. To capture a base you had to first send 20 sets of eyeballs to check and recheck the town before running troops. Bases needed to be closed just for all the finish work towns required and even then it would take a 2nd or 3rd set of troops to get a capture because we'd miss a building or four.
After this, briefly the flag was introduced and it barely took any destruction to get the white flag. It didn't stay this way long enough to change tactics.
After that we came to where we are now. Personally I got lazy, I kept using effective tactics and got my squad trained up to be pretty efficient. We took a lot of bases but a lot of our enemies started to realize that if they up from a nearby field they could fight back but only after we captured the field and landed so there was no real fun way to defend against the 'bishop horde'. This was unfortunate for both us and them because since they stopped defending like they normally would we were always in low heavy Jugs by the time it was time to fight. I found myself at a crossroads where not only was the enemy not counter-attacking like they normally would, but the base takers never got any air combat practice and pretty much forgot how to fight.
This is when base taking became nothing more than an exercise in boredom to me and forced me to look for new ways to capture fields that were fun again. This usually means leaving hangers up at airfields and hoping they fight back. Granted it's not as efficient or as successful but it is a heck of a lot more fun than working on a base taking assembly line. It's also allowed me to fly a greater variety of airplanes and learn how to dogfight a bit in planes that are well suited to flying low and relatively slow.
Sometimes I feel it's best to pull midwar shananigans or even close a whole field down to get a foothold but I prefer a variety of tactics and a variety of planesets.