I don't think the stock market matters to most people and it certainly should not be used as a proxy for general economic well-being, but I don't think it falling several hundred points in a couple of days is "good," either (probably one could make a complex argument for why this might be the case, but it certainly isn't obviously good).
This falls under my "media criticism and Trump criticism are not the same" point. Members of the media who tout the TRUMP BOOM should be criticized if they don't similarly tout the TRUMP BUST (whatever they base that on), but that isn't the same as "haha, Trumpy, where's your stock market boom now?"
And the thing is...as horrible as the Trump tax cuts for rich people are, it isn't actually crazy to think they'll be good for the "economy" - GDP, unemployment rate, etc. - at least in the shorter term. These things increasingly don't capture in any meaningful way what economic conditions are like for most people, but all things equal... rising GDP and falling unemployment (and, yes, a rising stock market) are probably good, relative to their alternative directions.
