Sudden Extermination

[Kai]

Is there a reason that when I'm doing Capture Missions that there's a chance that it becomes an Extermination Mission in the next 30 seconds or so. There's a reason why I'm doing Capture Missions and not Exterminate Missions, and imposing this sort of system to make the missions "longer" is very counterproductive. An example of this is farming for Argon Crystals in the Void, and of course they don't drop as much when you need them, but if they do drop - it becomes longer because Lotus decided that you need to kill X enemies before you can extract or even roam around the map to look for resources. 

Would DE ever consider removing this system and just make the missions as it is?

[Psychonosis]

I always thought it was caused by alarms, but I've been told that it's random.  But it you capture the target quickly and without anyone raising an alarm it seems to almost never switch to exterminate (for me, survey size = 1).