United finally registered a victory against Swansea on Saturday after a terrible start to 2014.
The 2-0 win, courtesy of second-half goals from Antonio Valencia and Danny Welbeck, should at least quieten the noise building up around manager David Moyes, even if a trip to Chelsea next weekend is likely to see it grow again.
Fletcher's frustration is that United's players have not been able to stop it much earlier.
For that may have ended the debate about Moyes' relationship with his players, suggestions of disenchantment over perceived preferential treatment of Wayne Rooney and even Sir Alex Ferguson's presence at matches becoming an unwanted sideshow.
"It gets us angry because we know it is not true," said Fletcher.
"We are there every day. The players are fully behind the manager.
"And Alex Ferguson being in the stand has no bearing on anything. It is great to see him there supporting the team. It would be a worry if he wasn't.
"We have got to believe in ourselves and keep a close-knit group, making sure that the experienced players are guiding the younger players in the right way. Winning games helps that."
There has been a feeling, going back long before Moyes' arrival in the summer, that United's army of critics were waiting for the club to fail.
That day does appear to have arrived, giving oxygen to all manner of debate, including over Moyes' future, even though there has been no such demand from the Old Trafford stands and leading United fanzine, Red Issue, has conducted a poll that puts the figure of those who support the Scot to be at 72.98 per cent.
"It is as if some people have been waiting for it to happen and are really relishing it," said Fletcher.
"We've got to use that as fuel to prove them wrong.
"We have got some great, talented young players in this squad. We have to keep reiterating to them that they believe in themselves.
"They will come through it without a shadow of a doubt and will be better and stronger for it.
"Hopefully they will be the ones passing on advice to the next generation when I am long gone."
For Fletcher, his vast experience brings added responsibility at a time when, by rights, he should be free to continue his quest for full fitness after successfully coming through surgery to combat ulcerative colitis, which threatened his entire career.
Not that the Scot is complaining.
At 29, he is old enough to remember the dark times between 2004 and 2006, when it seemed the club's era of dominance was at an end and Roy Keane delivered his damning verdict on MUTV, which included Fletcher, the after-effects from which are still rumbling on.
"I have been in situations when we were written off and booed," said the midfielder.
"At those times I had experienced players around me who backed me and gave me great advice.
"I am just playing on experience."
United will hope Rooney's groin injury has responded well to the warm-weather training in Egypt he has been sent away for.
Whether Robin van Persie is fit for Sunday's trip to Chelsea is another matter entirely, with the Dutchman's return date from a thigh problem that has kept him out for a month presently unknown.
Normally, a trip to Stamford Bridge would not be an occasion to relish.
However, having won there last year and with present expectations so low, it might turn out to be the best test United could be presented with.
"We will be all right," said Fletcher.
"Sometimes in bigger games you really come together. It brings out your best performances because you are really focused and really intent on proving people wrong.
"Going to Chelsea is a great challenge.
"We can take some confidence from beating Swansea and are fully confident of going down there and getting more of the same."
Source : PA