Re: Why did they bother...
If Paramount/Roddenberry shared that belief, The Next Generation and its sequel series would not exist. Yes, the NG ship is another Enterprise, but Picard, et al, were new to audiences.
Different time. There wasn't seven-hundred plus hours of Trek.
"If I hadn't tried, the cost would have been my soul." - Admiral James T. Kirk, Star Trek III: The Search for Spock