The fundamental issue is the dev didn't decide whether anyone is expensive or cheap, so it's not directly intentional design; it's only indirectly related since it's based on the arbitrary value the girlpack creator decided, as it stands now. So, if most girlpack creators put 0 popularity, then that's totally valid. It's not "cheating" because the value was arbitrary, perhaps intended for VC mechanics, and isn't related to other skills/stats, which I think should impact the price rather than suggesting it be more random in the future.
Again, I think the randomness is something that I would not like. For instance, if you disassociated price from popularity and made it completely random, then popularity would matter even less. You're right in that there is a logic, if popularity works as intended, increasing the draw of customers, thus increasing earnings; but I'm not sure there is such a strong relationship between popularity and earnings versus other stats and unlocks.
I wouldn't mind differing prices for different respective earnings levels, but only adding random prices would make the salary/wage disconnect worse, not better, in my opinion. In your example, you're imagining prospective employees with differing experience and proficiency levels being hired for different salaries, but the reality of implementing this would be an even greater discrepancy between price and revenue, meaning bottom rung prospects would be expensive while skilled workers might end up cheap. Whether we randomize popularity linked to price or randomize price in isolation, I think the end result would be a worse experience, especially for new players.
That said, Disgruntler did mention making a script to randomize popularity with the option to scale it to training stats and work proficiency, so that's much better than just randomizing popularity or price, imo.