EIP-2 Signature malleability: Why low s instead of dropping v?

[wjmelements]

I made an ERC for low-v.

ERC-8111: Bound Signatures

Bound Signatures Bound signatures are ECDSA signatures bound to a specific v. Constraining the y-parity allows signatures to fit into 64 bytes. Background ECDSA signatures recover two public keys for the same hash. ECDSA signatures are recoverable when they indicate which of the public keys corresponds to the signing key. Previous developers signaled which using a y-parity bit. In Ethereum, this bit is encoded as v. ECDSA signatures (r, s) are malleable; the s can be reflected across n/2 (…