A Possible Reason Harley Sawyer Targets 'Problem' Children
Now, 'targets' is a bit of a strong word given that we have two total examples. But you know what they say: Once is a coincidence, twice is a pattern. Also these represent 2 of the 3 (Rabie Baby being the third) confirmed cases I can recall where Harley himself singled out a specific kid to be turned into a toy instead of just submitting a list for the higher-ups to choose from (like with CatNap).
The cases in question are Quinn Navidson for Yarnaby and Kevin Barnes for Doey.
Quinn's 'problem' was that he pulled the heads off toys to mix-and-match them so he could make them prettier. Personally, I think that's not super odd behavior in a toy factory that makes Swapimals. He was probably inspired by CatBee or PJ Pug-a-Pillar to try and make his own! Sadly, Quinn's counselors (according to Harley, at least) did in fact consider this troublesome behavior.
Harley pulled out all the stops - though manipulating a lonely orphan when you're visibly an authority figure isn't exactly playing on hard mode - to con Quinn into doing a bit better at the GameStation so he could turn him into Yarnaby.
Kevin was even more explicitly 'troubled' than Quinn is, with the unnamed Scientist #4 outright calling him a 'problem child' when he raised (frankly fairly reasonable) objections to turning Kevin into one-third of Doey. Sadly for Kevin (but fortunately for whoever would have replaced him), Harley overruled #4 and used Kevin anyway.
But why? #4 speculated it was because of Kevin's high GameStation scores, but I found another explanation. It's buried inside the Red Maze from Chapter 4's Icepick ARG. Specifically this screen:
Harley thought he was merciful. Pair this with the line in the Sawyer's Secret tape where he rants that he "gave them purpose" and it all comes together. Visibly 'problematic' children would be the ones least likely to get adopted. And thus the ones most in need of 'saving'.
Harley explicitly viewed every subject as spared from the fate of becoming "another drooling automaton out in the world." But that's not the only issue problem children would experience. First, they'd be passed over, rejected by the only people with any hope of improving their lives even a small amount. Because they weren't enough. Because they were in some noticeable way, too flawed.
Sound familiar?
Of course the person who's still not over getting kicked out of the Young Geniuses program for his own personal problems would see himself as 'saving' others from that kind of rejection.
This is, of course, an incredibly deranged worldview. Children who aged out of Playcare without being adopted would probably be very sad that nobody adopted them, but the mutilated experiments are a lot sadder! Harley values purpose (becoming part of something great) over comfort (not being turned into a toy and used for slave labor). He seems to apply this principle to himself as well, snapping out of a pleasant memory because he has more important work (mad science) to do:
In conclusion, Harley targets problem children because he considers being sacrificed on the altar of Playtime's grand goals to be a genuinely better fate than rejection.