Poorly lit
Is it me or is it kind of hard to see anything in this movie at times even when the scenes take place in the daytime?
I call movies that are considered 'bad' hated movies.
A lot of the 70's Kodak film stock (especially kodak 5253 stock) was notorious for poor quality. Many films suffered in this era suffered from this "look". Kodak got a lot of flack and lost some big directors for a while until they corrected the issue.
Since the film used a lot of intermediate film stock for special effects, this would also compound the issue during its final transfer.
If they have the original negatives they could reprint it on new stock, or do a direct digital transfer to improve image quality