Symptom: Specialists may exist, but people become generalists because they can't depend on other specialists to help them. (A lack of teamwork.)
The reason organizations exist is to accomplish more than an equal number of individuals can do.
Of course, if everyone in the organization were a generalist, then the organization would not perform any better than an equal number of individuals. Everyone would be the "jack of all trades and master of none."
Organizational performance is dependent on specialization. When people focus on excellence in one discipline, they bring depth of knowledge and experience to each project, accumulate experience, and reuse their knowledge and past work to save time and money.
Put simply, the more people specialize, the greater their depth and the greater the potential performance of the organization.
But there is a catch. The more people specialize, the more they become dependent on teamwork.
People cannot specialize if they can't get help from other groups. Without teamwork, people have to be self-sufficient generalists to get the project out the door. Said another way, people may feel reluctant to subcontract pieces of the work to other groups, and would rather do everything themselves.
The bottom line is simple: teamwork is essential to organizational success.
Another (more generic) way to state the problem is as follows: