The second engine only helps in the case of a single engine failure. The parachute helps in case of
- mid-air collision (well, most of them)
- loss of control (if not too extreme / too low)
- structural failure
- dual engine failure (e.g. fuel starvation, fuel icing) and no landable terrain
- severe icing encounters (boots have given up, freezing level on the deck)
- engine failure over mountains with mountain tops above SE ceiling
The Cirrus has the parachute primarily because the co-founder of Cirrus, Alan Klapmeier, had a mid-air collision where the other aircraft crashed and the pilot died; he himself barely made it to the ground with 3ft of his wing missing.
The case for a parachute in a light twin is almost as strong as in a light single - but the market will be much smaller.