Sorry this is a little long;

1) Baader–Meinhof Phenomenon. Two of my relatives have died from OD and I've lost a close high school friendship due to not wanting to engage in them myself, so I'm also someone who pays attention to drug depictions in media, in and out of DWRP. I try to be very cognizant of it when I feel it's appropriate for any of my characters.

2) I work in medical and I can tell you statistically a LOT a lot of people formerly have or currently do engage in casual/recreational drug use of the big three (nicotine/alcohol/marijuana). Media doesn't always depict these accurately, but, often this influences public perception (good or bad) of drugs.

There's a lot of interesting (sometimes horrifying) history to unpack as an American (Prohibition era policies, birth of the Hay's code in Hollywood films & censorship, indie films and vs Paramount and overruling of regulations the 60/70s, to Regan's ~war on drugs~ in the 80s to EIC to ONDCP to unregulated digital media in late 90s/early 2000s and internet-born media/rebirth of indie films and earnest drug depictions to things like Prism Awards... and so on) BUT...

I like to think DWRPers are very savvy, generally very media-literate, and can sniff out when drug depictions are or aren't accurate, as in relation to how they might choose to or choose not to incorporate substance use into their characters.

4) That said, tell me how many games haven't used mind-altering or some kind of "status effect" mechanism as an event to get characters to interact who normally wouldn't. Humans have been sitting around bonfires getting drunk/high as a means to interact for eons, we have our characters do it in DWRP too, convoluted or coded or idealized or otherwise.

5) Hard drug use in characters in DWRP I find extremely rare. If you're noticed this frequently I'd (not unkindly) point back to 1).

I play one character who does hard drug use. Playing out the "yucky" parts is always on the table as I put in my permissions, but I find any time I tentatively bring it up people get (very understandably) very uncomfortable very fast. It's a hard, emotionally draining, horrible thing to go through as a supportive person, as I can personally attest. So I feel like that ties into the already-discussed fantasy-escapism element of this hobby that a lot of RPers (not just DW) prefer to not engage in so much. Which is perfectly fine!

I don't think it's anyone's place to tell anyone "you aren't RPing this drug use right!!" or, "you didn't prep that twink's butt for anal SO UNREALISTIC!!" that's not the thing to do in a fantasy-escapism imagination hobby where no one is hurting anyone and we have literally no public social influence on anything. People could be exploring whatever "taboo" subjects for a myriad of reasons, and exploring it in their characters or scenes or events to whatever sliding scale degree they feel comfortable with.

Lots of reasons, OP. You're not weird. Try not to overthink it because I promise you most of DWRP probably isn't either. It's fine to have personal preferences, it's fine to wish for more realistic depictions of things. You can find your crowd who matches your similar preferences, and maybe even come from a place of having similar personal experiences too. They are out there.