I think you raise an interesting point. Troubled romances can come from circumstances that are outside of the characters' control, or from their own human faults, and often is a combination of the two. From that end, having a "normal" person develop feelings for someone working outside of the "norm", ie. a prostitute, can raise some interesting questions and challenge our feelings and expectations towards a "normal" romance just as well as say, a classic Shakespearean tragedy.
The societal norm for a long time has been to disregard and actively look down on people in the skin trade. Whether that's right or wrong is a matter of personal value, but the current iteration of progressive societal values say that we at least can't deny that sex workers are human beings who deserve the same rights as anyone and shouldn't be stigmatized just for how they earn a living.
I don't believe that this is a notion that is accepted by most, to be honest. I have no qualms with dating someone who's done sex work, but I would draw the line at dating an active practitioner of the trade. Many others may not feel the same, they wouldn't want to date someone who's engaged in the business in any way, and that's totally cool as well. People are naturally going to differ in how they react to controversial subject matters.
But, this game challenges you to consider the people in these circumstances and engage with them, and see for yourself how you respond when you do get to intimately know and understand women who are put into these positions, even if you're someone who frowns upon the trade (which again, is a totally legitimate belief).
I've easily developed feelings and genuinely care for the well-being of the main characters who have been part of the debauchery, despite the fact that they are essentially whores. One of them even goes into it willingly for nebulous reasons, and doesn't have the excuse of desperation like the other two. And yet, I still feel deeply empathetic all the same.
There's power in how the game was able to make me think and feel like this, and though this is obviously erotica and not a social documentary of how sex work functions in real life, it still provides a perspective to look at and engage with our own preconceptions of what sex workers are like. The game even offers a choice: you can always choose to treat these women who have picked their poison with contempt and "give them what they deserve", if that's what you really believe. But you can also push past that and see that there's more to these characters than their sexual worth.
Sorry, that was a lot of rambling not necessarily directed at your question per se, just thoughts that have come up as I've played. My point is, the game challenges you in a provocative but effective manner, and I think it's awesome.