2. There isn't a category on glassdoor.com for network protocol developers. You don't see BLS data breaking salaries out based on the specializations you list.

3. If someone puts out a job listing for 'backend developer', you still don't know what your day-to-day will look like at you new job. Contrast this to 'pediatric nurse practitioner'.

4. We don't say to our bosses, "My specialization is X, but you want me to do Y work. We need to hire a Y person or you need to promote me to 'X engineer' and give me a raise."

5. Managers don't think much of sticking a rookie frontend developer on some backend tasks with no training or mentoring. "You'll review the code before it goes in, right? What's the problem?"