Because the expertise turns out to be vendor training or industry qualification rather than knowledge of the petitioner's own product, process or procedures. The standard is internal origin, not difficulty.
Vendor certification is not company knowledge
A specialist who is certified on a control platform, trained by a component manufacturer and highly experienced across the industry is describing a person the U.S. market can recruit or train. The classification asks for knowledge of the petitioning organisation's own product, service, research, equipment, techniques, management or procedures, or an advanced level of knowledge of its processes.
The honest test is to ask what this person knows that a well-qualified outsider could not learn from published sources and vendor courses. If the answer is a specific internal method the company developed, refined and documented, there is a case to build. If the answer is that the person is simply very good, the petition will read that way too, and the difficulty of the work will not rescue it.