The Prop Wizard model creator is an engineer with an analytical mindset, working full time and following sport closely on the side.
He thought that if sports books can manufacture long term profits, then we should be able to reverse engineer the process and flip the odds in our favour.
A bookmaker's edge comes from pricing, not from picking winners. So the model does the same thing in reverse: it works out what the fair odds on an event should be, and only flags a bet when a bookmaker is offering more than that.
Once the model had proven itself over the long term, the next step was to share it, so other punters could find value they would otherwise have no way of seeing.