Playing the devil's advocate, I can think of quite a number of things:

• An unnecessary cost increase for someone not needing them
• Occupying space that could be used by features I would use (e.g. more memory, an SD card slot, a second SIM slot...)
• An extra feature to maintain, provide driver updates, etc.
• An extra thing that could break, potentially affecting other things I would use

Those are just the things I could come up in a few seconds. I am sure I could come up with more given the time