I don’t know, how important is “that important”?
Yeah, quite a bit of vagueness to the question, but kind of fun so...
They are one of the key numbers on a player stat line, so they are that important.
They account for x% of runs scored in College level and above, so they are that important.
They are important enough that bat regulations are monitored and sometimes changed due to their frequency (I know, safety first).
They are important enough that the HS and college world is frequently discussing how fewer there will be with the bat changes.
They are the subject of great debate as to who should legitimately claim to have hit the most.
The players who can hit the most will find a spot on a team and get paid very well for doing so.
They hold a separate competition for them at the MLB All-Star game as well as many other baseball events.
They are what everyone is expecting when first hearing “Casey at the bat”.
The term is used in all aspects of business as an indication of an ultimate success.
Few things get large crowds to make more noise.
People line up in streets and on rafts ouside of stadiums for hours for the chance to catch one.
Some otherwise lousy human beings are practically immortalized because they can hit them.
All that being said, you can still win a game without one.