Segwit nested into P2SH was thought as a way of transition from legacy to segwit (bech32).
While nested segwit does reduce the transaction weight, it is still not as efficient as bech32.
Changing user habits is a tedious process. Moving from legacy to nested segwit is definetely a step in the right direction.
But the goal should be to get widespread bech32 adoption. It doesn't just improve the user experience, but also contributes to the overall network health.
@OP:
Is there a particular reason you want to use an legacy addresse?
General rejection towards segwit?