I didn't look at it that way. That the number of towers correlates to the number of active towering guilds. I guess that makes sense, but the design of some towers should be changed when it comes to spawns. 
Also i still think having a door with HP blocking the flag room and lowering the flag health would be a cool idea. It would stress "defending the door" because once it breaks the guild holding it is kind of screwed. 
Also, I hate the idea of guilds holding a tower ALL day long. Maybe this is because the "Tower guilds" now are almost temporary, hit 1,000 and they stop. Maybe once the notorious "guild update" comes, and this whole "temporary 1,000 tower guild thing" is gone, towering will be better. Hopefully guilds become multipurpose. Would it be more fun to log onto 7-10 HUGE  guilds that dominate in Towering/Sparring/baddies/pking/events that always have 15-30 people online (expecting the guild member limit to change) or is it more fun with small inactive guilds. In my opinion I would love there to be HUGE guilds with a 60-75 member limit. Long as there remains some competition, if all the best PKERs and Sparrers join the same guild, it would kind of suck.