It looks like a cool project but I'd not describe it as a "free Strava" as the most common features of Strava are free and the value of it is the community. Getting motivated by seeing your friends finish activities seems to be the biggest selling point (apart from supporting a lot of different sports, not specifically mountain biking) of Strava.
Also, Strava has spent expertise around topics like privacy and safety and made opinionated design decisions based on those. Have you considered your take on these topics? eg: Can someone make a random segment somewhere and find all the people who bike there?
One of the most useful features for me, comparing my performance on segments over time, is no longer free on Strava. They give you a greyed out portion of the list showing the last two visits with a link to subscribe.
I'd agree I don't think of this as a "free strava" -- that was for getting attention.
Does anyone know if Strava is profitable or if it is still burning cash? Tough business - I started using it in the early days and was happy to be a paying customer when they started offering that. (A) to help fund more services and (B) I hate the free software model which I realize Strava was originally as they bootstrapped a user base.