I have been flying B737s for 25 or more years. When I first started flying them, we were required to check outputs. Since about 1986, Boeing removed the requirement due to increased reliability and feedback over many years of monitoring system failures. I have recently joined and airline that thinks it is flying -200s, in spite of the fact that all they operate is -800s. They require me to check these outputs after start, regardless of Boeing's procedures. As mentioned already, if the outputs are bad, Generators won't come on line. TRs, if not working correctly, will show all sorts of other problems.
they also insist on the A Hyd. pumps being off for pushback, in spite of the mods Boeing did to the system about 20 years ago.
Such is progress.