That was also my take-away regarding this idea.
20% cut? For match-making on private music lessons? Fuck that. Our local music store charges less than that for renting an hour in a soundproof room! And the discoverability/match-making "platform" is a free bulletin board next to the restroom...
Also love how that email described the radical act of checking the local music store's bulletin board (or going and asking a friend/coworker/etc. for a recommendation) as "under-the-table neighborhood activity".