When they're outgunned yes. The fort was still under construction and didn't possess the armaments to fend off a full scale seige. The cannon balls didn't have the needed point detonating fuses so they couldn't explode. What few shells they managed to fire were ineffective. Not taking the opportunity to surrender was a terrible mistake.
Which shows that it was of no threat to the new Confederacy. Thanks for showing that. So the South fired on a harmless federal installation....why? To start a war they couldn't win. Pretty stupid....but not surprising.
Fort Sumter was at the heart of the central controversy between the North and South. Tariffs were imposed and collected from merchant ships entering the harbor. It was also a key hub for the blockade set up by the North. It's strategic value made it a high priority for seizure.
It seems all of this is news to you. Are you sure you want to keep revealing your ignorance of American history?