You can make this argument about most software developers too, while they may create unique applications, they are mainly using the "already known" (existing languages, API's, etc)... You can then go on to apply this argument to nearly any other "white collar" job, accounting is "the application of the already known", etc..
White collar does not mean that you are in a research field and pushing the limits of knowledge, from what I understand it has long had an entirely different meaning. Personally, I feel that white collar / blue collar are very outdated terms. I often feel that a software developer is somewhat of a modern blue collar worker as its a creative trade and very different from a "white collar" job such as a sales or marketing job.
White collar does not mean that you are in a research field and pushing the limits of knowledge, from what I understand it has long had an entirely different meaning. Personally, I feel that white collar / blue collar are very outdated terms. I often feel that a software developer is somewhat of a modern blue collar worker as its a creative trade and very different from a "white collar" job such as a sales or marketing job.