The first example cites "the worst performance ever".
Taking that as a given how bad was it?
This season's vaccines were around 25% to 30% effective in preventing adults from getting sick enough from the flu that they had to go to a doctor's office, clinic or hospital, according to a CDC report this week.
Of a hundred adults that
would have had to seek medical treatment / take a day off (had there been no vaccine) 70 adults went to the doctors and 30 did not.
Children who were vaccinated were about 40% less likely to get treatment at a doctor's office or hospital.
(As above, of one hundred kids that would have gotten sick, 40 did not )
The questions really should be .. did people die that could have been saved, was it cost effective to vaccinate a hundred million people to reduce the percentage of those who contacted flu and then got sick (and did the vaccination reduce the numbers of people in contact).
As it stands, by your examples, the flu vaccine didn't perform well that year, in comparison to others, but it hardly looks as though it had no effect whatsoever.