I'm more curious about why there's such inconsistency in the behavior across so many TVs. I'm sure the Switch is sending some sort of signal, but it hasn't affected a single TV I use so far, where I'll leave it docked and on standby for hours.
Because some television manufacturers have different software that detects always-on connections, or can bypass electronics that tend to randomly turn on and off. This is a Switch issue, it just impacts Samsung more because they use a proprietary one connect digital box that automatically detects active connections and because televisions like the KS8000 sold ridiculously well for gaming last year.
I mean why is the Switch HDMI being randomly powered on and off? Either keep it always powered like some cable boxes or media boxes, or keep it off until you actually turn it on. Instead, Switch owners have to wait for television manufacturers, computer monitor manufacturers to come with a solution for Nintendo software quibbles.