Nobody in 1977 save George knew there would be another one though. I heard many of the same complaints back then. Phrases like "carboard cutout characters" and "junk food for the mind" were tossed around a lot.
Now that the movie has made so much cash, I'm waiting for the inevitable "I worked on the biggest film of the year, and therefore deserve more money that I was paid at the time" tabloid crap that was pulled with Star Wars. ;)