I can agree with you on gregtech being a tech mod, but there is no other mod that makes the game this hard and I enjoy these challenges. I seem to view gregtech differently than other players. Most view it as another mod. I view it as an extension to vanilla Minecraft that allows you to achieve more at the cost of more time. If I have a bronze age grinder that means I can get more out of an ore than I could in vanilla and therefore that makes greg's annoying nerfs just another step forward in exchange for good things. To sum this up I think Gregtech with hard setting all the way up is a bit to easy in some areas. Specifically animal farming. You have to pay more for better things and getting tons of materials on one piece of ore should be more costly.
Though one thing that does make me crazy is when greg adds a whole new step of challenge and doesn't add anything there. If he is going to add nerfed animal drops he should at least add some form of electric sheer that can get 1.5 output on wool or a skinning knife that if you kill a cow or chicken with will get you more leather or feathers and maybe even a butcher's cleaver for getting more meat and even getting lamb chops from lamb.