You really should respond, at least tell them why you chose to be alone, or maybe go hang out with them, doing stuff with other people can be great fun even if you don't wanna hang out all the time, and you might get out of practice with socialization if you don't. And there might come a time in your life when you find yourself desperately needing friends, not just because you're lonely but perhaps financially screwed over or something, a time you probably won't see coming till it's too late.
Even longer term, eventually the soil will deplete and there will be widespread famine (though not for the upper classes lol), you'll need friends to watch your back then. Or perhaps we can undo the metabolic rift before then, I hope so, I'm not one of those creeps that looks forward to the apocalypse. Gardening with your friends and neighbors would be a good first step to that.