No. Young chimney sweeps captivated Romantic writers, just before the Victorian period, as a symbol of the injustice and exploitation of industrialization; William Blake, in 1789, wrote a poem from the perspective of a sweeper boy called "The Chimney-Sweeper," which powerfully condemns the clean, warm lives that rest upon such filthy, dangerous exploitation (it's an amazing poem). Charles Lamb wrote an essay about young sweepers in the 1820's which, while characteristically mild in its critique, also refers to how degrading their lives were. So basically people had been aware of how terrible the job was for decades already by the Victorian era.

The main primary source for information on Victorian working-class jobs and lives is Henry Mayhew's Labour and the Poor, also called London Labour and the London Poor, a pioneering work of sociology and urban ethnography that combined statistical data with archival records and in-person interviews. He quotes from a Parliamentary Committee formed to look into the condition of child sweepers which found, in 1817, that "It is in evidence that (1) They are stolen from (and sold by) their parents, and inveigled out of workhouses; (2) That in order to conquer the natural repugnance of infants to ascend the narrow and dangerous chimneys to clean which their labour is required, blows are used; that pins are forced into their feet by the boy that follows them up the chimney, in order to compel them to ascend it, and that lighted straw has been applied for that purpose; (3) That the children are subject to sores and bruises, and wounds and burns, on their thighs, knees, and elbows" (page 347). So the kids had to be forced up the chimneys by sticking their feet with pins and literally lighting fires beneath them. This Commission led to the outlawing of chimney-climbing boys in 1829, so by the beginning of the Victorian period sweeper boys had been replaced by mechanical solutions using rods and gears, though apparently some master-sweepers found them less effective than boys (356).

So basically chimney-sweeping boys had been outlawed by the Victorian period, and when they did exist in the Romantic era, they were extremely unhappy; unhappy enough to bear the symbolic weight of all the injustices of industrialization on their filthy shoulders. If you have formed an opinion of happy chimney sweeps from Mary Poppins, I regret to inform you that this is not an accurate representation. There is a street sweeping boy in Dickens -- Jo in Bleak House -- who is arguably not conscious of how much his job sucks, but Dickens brings the full rhetorical force of his outrage at social injustice to bear on the plight of Jo and others like him.

I have never made a comment here before so I am uncertain about bibliography formatting. My only source used was: Mayhew, Henry. London Labour and the London Poor: A Cyclopedia of the Condition and Earnings of Those that Will Work, Those that Cannot Work, and Those that Will Not Work, vol. 2 (London, G. Newbold, 1851).

Edit: Oh wow, reddit gold! I'm going to caper around the yard on my crutches like Tiny Tim on Christmas Day.