I agree it's a dumb design.  Relays do go bad and if you use resin, you have a mess to deal with trying to get them out.  A real PITA.  Relays, especially high-amp relays are pretty robust and can withstand some water and more importantly vibrations.  Although high-amp relays usually have screws on the terminals and not just blades.
Also a bit silly to use solder-less connectors.  Should be using a plug connector.
I really like my setup though.  Simple and easy to setup and bypass/fix if needed.  Although if I was going to do anything differently I'd change the 40A relay with a 75A relay but I haven't had any problem once I up'ed the wiring and replaced the ATC fuse with a circuit breaker.