The companies that produce the engines all want hybrid stuff as a marketing / tech cross over tool. The only way you'd get an alternative would be if the FIA mandated it and then found someone to provide it. Ferrari, Mercedes, Renault and Honda won't be using someone else's engine so they would all leave, unless one was chosen to supply - the others would still leave, however. The result would be a one-make series in effect with engine and gearbox being provided by the FIA's suppliers. Unless the rest of the car was mandated by the FIA, you'd still end up with the team with the most money winning as the aero side would be open and that's expensive.
Do we want a one-make series as F1?
Of course, you could do a two-part Formula with a split like the LMP1 / LMP2 system. Manufacturers in F1A and "garagiste" teams in F1B. The latter using standard engines, gearboxes and maybe some other stuff. If it was cheaper, you'd get people entering teams. That would bring more drivers forward too. Bigger grids would be great, although some of the tracks might be a bit too confining for large grids. Allow F1B a bit leeway with aero, or fuel, or weight in order to prevent them being lapped in 5 laps or fewer!
Turbo says "Dumpster sounds so much more classy. It's the diamond of the cesspools."