What "crazy crap" are you talking about? I get that HTTPS might be overkill for some situations, but it's not difficult to use and every client device supports

What "crazy crap" are you talking about? I get that HTTPS might be overkill for some situations, but it's not difficult to use and every client device supports it. If you came up with your own signature-but-no-encryption protocol (maybe something similar to DKIM, actually?), nobody would support it. Even if they did, I'm sure that some people would use it when HTTPS is a better solution, just because they don't understand the tradeoffs. A standardized overkill solution that covers most use cases is probably better than n+1 standards with different tradeoffs.