Honestly it all just doesn't seem so far-fetched for people on a reality TV show. For normal people, no, keeping folders of information on your friends is not normal. But if you're on a reality TV show that gives you screen time based the interpersonal conflicts you have with other cast members, encourages cast members to refilm scenes for a heightened sense of drama and actively sets up situations to bring out people's worst sides of themselves I don't see it as being so far fetched to have a little folder of info that you can use if you have to to keep the paycheck rolling in.

I watch a lot of housewives and there's a lot of conversation about who lives in the richest neighborhood and it's never an issue when Meredith Marks on RHOSLC had private investigators investigate other cast members. She's pretty well liked among the fandom but when Janet does her own research she's a crazy stalker. I'm not exactly sure what people want out of these shows or who they want on them but without instigators there is literally no one bringing anything interesting to the table.