I don't think people, even red blooded super horny American male people*....are really slobbering over their TV screens at Olympic athletes wearing bikinis. Not in a world where you can find far more salacious material to ogle over at the click of a button.
Meanwhile, the people in charge of beach handball have seen it fit to explicitly put it in the rules that women's sport is played in bikini bottoms.
"Female athletes must wear bikini bottoms ... with a close fit and cut on an upward angle toward the top of the leg," the rules state. "The side width must be of a maximum of 10 centimeters."
As people here have noted, they didn't even know this sport existed. Many a sports in the world competing for viewers and sponsorship money, and you have to have yours stick out somehow. Bare skin is their chosen way.
Or was until the Norwegians ruined the gig.
The base needs work much more subtle than your point on there being more salacious material available lets on. When NCB does their programming for the Olympic boadcast, they probably will choose women's beach handball over cayaking. When
you clickity-click-click on the remote for Olympic broadcasts, this is where you pause.
Maybe you're repressing you sexuality and the facade of sports gives you the needed plausible deniability to oggle away. Or maybe your internal Harvey Weinstein feels warm feel when sportsy girls get subtly enforced into these rules that are oh so essential for the integrity of the sport. Them internet girls who need their daily dose aren't much of a challenge.
Beach handball is not an Olympic sport btw. Beach volleyball with two girl team in bikinis is. Easy to confuse. And easy to see the rationale behind why some people thought there needs to be beach handball in addition to the normal variety handball.
"It's what fun-loving bikini-wearing young people normally do as a normal beach fun activity on hit summer days, and it was so popular that it just happened to become a genuine sport..." with federations and sponsorship deals and the whole she-bang. Yeah, right. But that's the implied story they're pretty much selling.
Remove the bikinis and what you got is normal handball (with maybe some minor tweaks to justify the existence of the bikini version) and two sets of handball federations with sudden excess of well-paid people in suits.