A complete lack of understanding. The average dev isn't going to have nearly the skill levels of the top pvp players. Not even close. And at the lower skill levels, the Merc/Commando is great. Easy to pilot, easy to do target acquistion, low penalties for blowing up your resource stack, too slow to need to learn how to plan out quick surprise moves, no utility so you don't need to do anything but pew, pew. In a battle amongst and vs. low skill players, the Merc/Commando does really well. So it is not surprising that the average dev thinks Merc/Commandos are just fine.
Now add in BW's ingame stat collection system and those metrics will just continue to reinforce the devs mindset that Merc/Commando is very strong.
You may see a minor boost to JetBoost in 1.7. Something like having it remove movement impairing effects and provide a 30% sprint ability for 2 seconds. That's it folks. Oh, and maybe some more nerfs to your damage output since BW thinks you do too much damage.
Sadly I think you are pretty on point here. It seems to be this way for all of the healing class dps trees. Not to merc healing is competitive either, but at least it can be used if in skilled hands