That's what Nepalese guides and genuine summiters say. Photoshopped pictures of happy climbers on top, bribes, and so forth, are tarnishing the accomplishment.
Personally, I can't imagine why anyone would do such a thing: you'd presumably make such a climb seeking personal satisfaction, so what possible value would a false claim have? But that's just me. Back when I spent a lot of time hiking and climbing in the Rockies, I deliberately sought out, say the second highest peak in a state, knowing that the highest peak would be swarming with people determined to "bag" it. Most of these peaks are walk-ups anyway, so big deal.
My other opinion on this subject is that in fact, Everest has become too easy to climb - from what I read, the mountain is now jammed with weekend warriors being hauled up the slope by Sherpas, and the majesty of the mountain and the isolation of the area has been ruined. Fortunately, there are enough ice falls and avalanches each climbing season to knock off a handful or two of these intrepid city folk - reduces the numbers a bit and serves as a reminder to wannabes that high-altitude mountaineering is in fact not just a tourist adventure.
All that said, this is not actually a new development: fraud associated with Mount Everest has been going on at least since 1995, when Hillary Clinton, born in 1947, claimed to have been named after Sir Edmund Hillary, the first to climb the mountain, in 1953. Perhaps the lady's parents were too busy dodging mortar shells in Bosnia to name her for six years, but most people doubt her claim.