I like these types of opinions that challenge entrenched beliefs, i.e. network effects etc. But in the end I don't think there's a contradiction -- if you have 30 people in the room speed dating, you have 30 people in the room. If you have 30 people on your app, you have 0 people on the app because most of them are there at different times and then they give up because nobody's there except them. People gravitate towards where everyone else is, in the case of a dating app it's where thousands of people in your area are, and for speed dating it's where 30 people per event are.