I don't really like "risk takers" but neither do I like "morons". I should be constructive here, then. What term would I use? Twits??
How about 'Darwin Award Contestants'?
"Award"may sound too positive to these people. I have just looked up definition of "twit" for alternatives ...
a silly or foolish person.
synonyms: fool, idiot, ass, halfwit, nincompoop, blockhead, buffoon, dunce, dolt, ignoramus, cretin, imbecile, dullard, moron, simpleton, clod; informaldope, ninny, chump, dimwit, nitwit, goon, dumbo, dummy, dum-dum, dumb-bell, loon, jackass, bonehead, fathead, numbskull, dunderhead, chucklehead, knucklehead, muttonhead, pudding-head, thickhead, wooden-head, airhead, pinhead, lamebrain, pea-brain, birdbrain, zombie, jerk, nerd, dipstick, donkey, noodle; informalnit, numpty, clot, goat, plonker, berk, prat, pillock, wally, git, wazzock, divvy, nerk, twerp, charlie, mug, muppet; informalnyaff, balloon, sumph, gowk; informalgobdaw; informalschmuck, bozo, boob, lamer, turkey, schlepper, chowderhead, dumbhead, goofball, goof, goofus, galoot, dork, lummox, klutz, putz, schlemiel, sap, meatball, gink, cluck, clunk, ding-dong, dingbat, wiener, weeny, dip, simp, spud, coot, palooka, poop, squarehead, yo-yo, dingleberry; informalwing nut; informaldrongo, dill, alec, galah, nong, bogan, poon, boofhead; informalmompara; vulgar slangknobhead; vulgar slangasshat; archaictomfool, noddy, clodpole, loggerhead, spoony, mooncalf
"she must think I'm a real twit"
I might go for "plonker" or "wazzock"