One could say “retalling” someone with over 50 million turrets and 145% weapons tech over 200 acres is an overreaction, yes?
Agreed, it's pretty uneven. There's reasons it doesn't make sense and then there's reasons it does.
First, there's the aspect of hitting dangerous countries in the first place. If you then make it difficult for them to retal for awhile, does that mean they're not entitled to hit back anymore? I wouldn't think so, unless you can run all the way until the reset ends. Then there's obviously GDI where one hit equals one hit, no matter how old or small it is. That's simply a reality that the meta game has to arrange itself around, and that's caused 1:1 retals to become fairly standard procedure. Finally, there's the land at stake. If someone can snatch 5000 acres when land is scarce, then regardless of whether it's a huge break or an old retal, a player competing to win is not going to want to leave that opportunity on the table.
Now that all makes perfect sense, but I'll still readily admit, if you take a step back again, and look at it from the 10,000 foot view, making a 5000 acre profit off an old meaningless 200 acre hit absolutely is rather absurd, no question.