Why is being able to amend the constitution important?

Without amendments, we are stuck with what some guys thought would be nice over 200 years ago. A few things we took out of the constitution by amendment: Slaves count as 3/5 of a person. The incoming president must wait five months after being elected to take office. Electoral college for senators (now--can we get rid of it for presidents?) We also filled in holes that were evident in the constitution, and clarified more rights that people have. The Bill of Rights is all amendments--they wanted a working government first before they decided what limits to put on it. Women were allowed to vote. Someone figured out that if a president becomes sick but doesn't die, the government is in limbo, because the VP couldn't just do the President's job until an amendment was passed saying how it would be determined the Pres was too sick to do his job. Allowing amendments allows mistakes made by the writers of the constitution to be corrected, and for changes they didn't for see to be allowable.