To the contrary, they want to make the matchup for it's appeal to casuals first and foremost. Valentina and Joanna at least have some 'casual recognition' and drawing power. They even think Valentina is a 'killer' who is going to 'murder' whoever she is booked against (Montano, Eubanks) other than Joanna.
It's a rare WMMA fight that could headline a UFC PPV (what other WMMA fight do we think would draw as well as a PPV main right now?) . That's why it was their first choice to bail out UFC 230. Valentina vs 'who the fuck is that girl', not so much, even if they have 'earned their shot' more (according to some... hardcores?). Just see what kind of reaction Valentina vs Eubanks got. They had to scrap the matchup and go back to Valentina vs Joanna (screwing Joanna over twice).
Now imagine the reaction if the battle of the hardcore 'but they deserve it the most' got the UFC230 headline slot: Chookagain vs Eubanks...