I am a pathologist and clinical informaticist. @Napoleon1801 is right; it's a field with a lot of overlap with laboratory management and business administration, and it does not directly generate any RVUs. Because of the lack of RVUs, most informaticists (at least, those who do any significant percentage of informatics) work in large organizations. Most people who work in the field start by holding a position in their primary specialty that has an informatics component, and the informatics work tends to expand as one's career progresses and as you are able to demonstrate value to your organization. The specialty choice is, in a manner of speaking, a bet on the future. The specialty's value proposition aligns well with emerging trends: value-based care, population health, digital health, etc.; all of these areas could be considered "the future" of medicine. It can also be a springboard to leadership positions early in one's career.
Practically speaking, for pathology-trained physicians, I'd highly recommend looking at combined clinical informatics and heme/cyto/derm etc. fellowships. That allows you to shorten the period of training to 2 years total rather than 2 years for CI alone.