That does sound a more sensible interpretation to me. I know many in India (where vegetarian diets are prevalent) who eat meat occasionally when they suddenly crave for it, but are mostly inclined towards a veg diet. And they think of cannot eat non-veg foods for all three meals or even continuously every day for even a week unlike some others who can't do without meat in a meal. Perhaps bisexuality is also a spectrum rather than a 50-50 thing?

Or,

I eat $x at home, I am looking for $y on this service.

There are plenty of bisexual people I know that have open arrangements who are in relationships with a partner of one sex and are only permitted by that partner to date people of another sex by that partner (because fear of competition/jealousy reasons).

Some people only want romantic relationships with a partner of one sex while hookups with another. Some people have bi-cycles. Some people are attracted to a person of their own gender 80% of the time and another 20% of the time.

Many people, including myself, don't find the whole "cycles"/percentage thing attractive, though. Especially for a longer term relationship, why would you want to date someone who loved you for who you were only part of the time? Especially seeing as its something you can't change about yourself.

In reality I've generally found that many "bi" guys are just waiting for a "real" relationship with a chick, while doing guys on the side. Hell, even outside of relationships, most bi guys I've met would pick a chick over a guy 9 times out of 10. Some of that is due to the fact it's a lot rarer/harder for them to hook up with a chick vs a dude (latter being more open and free with sex).

If someone is bi, has a romantic/sexual preference for both and experiences periods where they really do prefer one or the other then a traditional relationship is probably not going to work best for them; something poly or very open seems like the batter option, where their partner is aware and agrees to it.