Pressing with a knife and then lifting is very much one of the techniques you can use with a painting knife (see Mark Making with a Painting Knife). Whether you like texture showing in paint or want the paint to be totally smooth is a personal preference. Both are acceptable, and the one isn't better than the other. It's merely different styles of painting.
Bob Ross almost certainly has some texture in his painting, you just don't see it as it's very difficult to capture texture in a photo unless the light is shining at an angle. Very few photos of paintings show the texture of the paint. It's one of the reasons for visiting art galleries and museums to see paintings in real life, that you can see how the painter has applied and manipulated the paint. As an example, take a look at this painting and then this close-up detail from it. If you only saw the overall painting, would you realize quite how thick and textured the paint is?
