More people feel comfortable riding scooters than bikes. There’s a stigma around “I can’t ride a bike”. There’s also less regulation on dumping scooters than on bikes. ;)
I don't think stigma was the intended meaning. I assume the poster meant something like doesn't feel confident enough riding bikes to do so in traffic--especially where bike lanes aren't well delineated and separated. Which certainly rings true for me. I can kinda/sorts ride a bike but I only learned as an adult and would never do so on a road.