This issue has been discussed many times over the years on various forums. Many asked Strava to creat a Tandem class to avoid this issue. Strava didn’t see it as a big deal and responded by recommending that tandem riders just open an additional free account and include “(tandem team)” as part of the user name. This would identify tandem teams that are stealing all those coveted Strava cups.
I have my own Strava account and we have a free account with tandem team in our name. So far, collecting too many Strava cups has not been a problem 😁. I record all my rides in my account by the bike ridden and our tandem rides in the free account. It works.
I think Strava is right, it’s just not a problem upsetting the sanctity of the segment hunters domain.