My feeling after years of study is that Lucas doesn’t want to be reminded of work he wasn’t happy with at the time and only reminds him of what he lost. Every movie he swore it was the last and that he and Marcia could settle down after, but by the time RotJ was done, she was gone.
Doesn’t change the fact that it’s film history and should be preserved, but I get his hesitation now.
It’s not spite, it’s regret.