I don't think there is anyone who would consider the "basics" of a G1000 -- a real one, as that's the point -- as anything less than what would be needed for a safe flight without breaking stuff and while maintaining nominal backups and redundancy. That does NOT include instrument approaches for a VFR flight. It does include checking the E and M busses -- as well as the two cooling fans and the standby battery and several other things unique to a glass panel -- for nominal conditions in preflight. It's all in the POH. Unfortunately, it happens to be something the Garmin sim doesn't do that well.
Call it "sniping" if you want, but your 20 minute claim was wrong. That was for teaching something other than what is needed.
Are you actually proficient on a G1000, or are you just a casual user who looked at it once?
For the record, I'm working on VFR G1000 proficiency. I have about 5 hours now in a G1000 182T. While I've never programmed an approach, I've certainly run through the preflight checklists, and exercised all the VFR features at least once. There is NO WAY this can be learned in 20 minutes. I still hunt for some things (like getting METARs for the destination), so I'm less than proficient.
Ron, your statements might make sense for an Aspen retrofit, especially without a GPS or autopilot, but an integral flight deck like a G1000 is a different beast. And while you're unlikely to break a BATD from screwing up like you did, giving that advice to someone flying a real airplane could have real consequences. You should know better.