Nobody, not even the attorneys for Mr. Flint's family, is denying Mr. Flint's responsibility for the accident.
If it takes breaking the law to break a Strava record, and Strava encourages people to break that record, then Strava is encouraging people to break the law. So, no, Strava encouraging its users to break records is not garbage. Plus, Mr. Flint does not have to have been "forced into it" for Strava to have some culpability.
Just because Mr. Flint is primarly responsible, does not mean that no one else has some culpability.
Hypothetically, if Strava started keeping segment times and records for motorcycles, and this incident and the SF pedestrian fatality occurred with motorcycles instead of bicycles, would you feel the same way?