OKW flak emplacements are a good example of how an emplacement should be designed. They cost fuel + pop cap and thus aren´t spammed. That being said they can still be useful if used right. They are actually decent after the changes to them in DBP. Much better way to design a static emplacement.
Again, I did not say that bunkers can´t be countered or even that they are OP. Just that they are annoying and poorly designed. Why should you be allowed to spam an unlimited of MG positions while having no pop cap? Makes no sense.
Of course it makes sense. Almost every RTS has static defense - Starcraft, Warfcraft 3, Age of Empires series, Age of Mythology, etc.
The whole idea with emplacements is that they are immobile, strong against one unit type, do not contribute to army or population, and require additional attention for the opponent to deal with correctly. That being said, countering a bunker just requires one flank. A penal squad can throw a satchel, an engineer can lay a demo, riflemen can smoke and capture anyway, rear echelons can smoke and run past with bazookas and kill it ... etc etc etc.
Talk about removing MG nests because you guys don't counter them properly is just non-sense. They have existed in since the dawn of RTS and will continue to fill a role as a strong immobile option for denying access to an area against a small number of basic units.