That seems to be a non-argument to me: you shouldn't implement TLS yourself anyways. And given that spiped is a younger project than say OpenSSL will mean less eyeballs applied to finding bugs. And the cryptographic primitives spiped uses are available in TLS as well.

TLS and spiped are simply two different tools, for two different purposes. Control only one of the endpoints? You'll have to use TLS. Want to secure communication between infrastructure you control? Check out spiped.