Ok, then what do you call the big asteroid impact or Mount Tambora? Look I didn't math out whether we could match it if we put every weapon in existence in a big pile and blew them all at once, but the combined yield of every test in history (plus the two dinky ones actually used against other humans) don't come close. Maybe the aliens could equally say "wow, what restraint, they harnessed such forces but were horrified by them and immediately swore off using the big new toys they were building."
Your view here is just self-centered. We are still buffeted by forces we can scarcely comprehend, and we have yet to do a tiny fraction back to the planet what it does to us. And the whole "they harnessed it for war, what monsters" thing...maybe one day an uncaring cosmos will send another extinction-class asteroid at us and we'll have another use for those weapons.
Also, it's funny everyone pointing out how the original tests were scrub-tier compared to today. Oppenheimer saw that first test and said he was become death. Well, 10^9 and 10^12 are equally unfathomable, but 10^9 is what we have at our disposal and 10^12 is what we're up against.