The reason why people were unhappy about Venus' withdrawl was because she did it shortly before she was due to play her second round match against Kournikova.
I was there remembering the huge crowds gathering there before the match, only to find out after many of them bought the tickets that she wasn't going to play. Then I think her excuse was kind of weird although I have no doubt there really was an injury. If not she wouldn't have bothered to show up. She was in fact practising at the ground two hours before the match was supposed to take place.