There is also the fact that at medium or close range, Fire Control will ignore Counter Measures, whereas nothing really ignores Armor Plating <.<
Absolutely. (Although, Extra Hull Damage does still cause 1 Hull Damage on a roll of 1.)
Note, too, if your opponent is taking Fire Control, then they aren't having as much punch as they would without it. In my campaign with Blacklancer99, capital ships routinely have Countermeasures and Fire Control. It's F'ing essential! They also happen to have highly accurate weapons (3+ is standard). I think we fought one battle where my ships had countermeasures and most of his ships did NOT have Fire Control. The story of the battle revolved around his ships not getting as many hits as my ships.
Have you read the Starfire books by David Weber? Much of those books are the story of strategic tit-for-tat with technology. The same has happened with Blacklancer99 and myself. We started playing with Countermeasures vs. Armor Plating. Over time, most of our self-designed ships have Countermeasures and Fire Control. Some have Armor Plating as well. But you are giving up something when you take these defensive techs. My ships tend to have higher shield ratings than Blacklancer's ships in the same class because I prefer defense. Blacklancer's ships lack the higher shield ratings but their main guns tend to have two things mine don't: ammo, higher ROF.
Anyway. I think Armor Plating is balanced. It does its job.