I’d half expect Strava to reduce participation – the ‘you can compete ‘virtually’, why bother to do it for real’ mentality.
You’re projecting the same old Negative stereotype on to all strava users or indeed anyone who didn’t show up for some local hillclimb event (and hence must be a Strava using wimp)…
Not all Stravarists are KOM Cheats, scared to enter real life races and is Strava really the only possible explanation for such a low race turn out?
How well publicised was the event?
Was it club organized? and if so what is that clubs like? welcoming and helpful or a bunch of insular gits?
To blame a low number of race entries on a bit of software seems a bit of a stretch actually IMO…