The paint roller helped launch the DIY movement more than any other painting tool.  An excerpt from a Business Week article entitled “Rolling Up Roller Sales” from January 1953 captured its impact:

When the home handyman—or his wife—sets out to change the decor of his living room, chances are he’ll do the job with a paint roller. Five years ago, or even less, he would have wielded a brush—or ducked the task entirely. The roller, teamed with new types of easy-to-apply paints, has done more than a bit to spread the do-it-yourself movement to home painting.

Commenting on early paint rollers and their users, a Popular Science article from 1968 remarked, “You weren’t expected to do well with one… the assumption was that you weren’t bright enough to paint with a brush.” Amateur painters appreciated how easily they could learn to use rollers and disposable covers, while some skilled painters lamented the devaluing of their abilities and knowledge.

The DIY movement and its attendant roller simultaneously devalued painting skills and knowledge and dried up the business of professional painters. By the mid-1950s, the painter’s trade estimated that do-it-yourselfers were completing about 80 percent of all indoor painting projects. My grandfather, whose skills and experience guided him both on the job and as a home handyman, felt that only traditional high-quality brushes delivered the best results. A brush gives the painter more control and finesse than is possible with a roller, especially the disposable variety. The roller requires less technique and labor than the brush, but it is also less versatile and consistent.

As some painters chose the roller for its speed and ease of use, they disinvested in the tools and techniques required for top-notch painting. Do-it-yourselfers can read about brushes and brushwork in how-to manuals, but they are not likely to handle the right tools long enough, if at all, to gain the experience and knowledge of a professional painter.