Let me rephrase a bit then. Ores have much value, but stone and dirt are about the same value as their name implies. In trade for not wasting resources on picks to break the cheap stuff in your way, you have a cheap infinite tool to muscle through the mass of waste while saving your expendable iron (or other) picks for things that hold a fair bit of value. Having once dug a 64x64 pit with mostly stone picks in vanilla, I can most certainly see the dramatic value of a tool that doesn't break. Even without much or any speed boost, a batpack and infinite tool let you do vastly longer mining trips without concern towards how much space you need for picks, or if you have to stop and craft a fresh one every time it breaks. In addition, it is my opinion that Gregtech is trying to extend the gameplay length of a given world by extending progression time. This is a preference issue more than anything and I feel it is a great thought when you might use the same world far beyond maxing your non-gregtech gear. Yes, you still will most likely use the same world for whatever you feel drawn to do but the extra flavor of increased effort for the best goodies isn't a bad idea at all. Not to mention the extra feeling of accomplishment you can have by doing it the hard way.