DPI i just incorrect. Use PPI if you really insist on that name.
That said, there is nothing gimmicky about the retina name. It's a device where distance to the display, resolution and screen size are such that someone with normal vision cannot distinguish between pixels.
High-PPI does not in any way pack the same information. It’s ambiguous and unclear.
The only thing that’s bad about retina is that Apple uses it like a trademark. I would love it if any company could call their HD TVs retina displays (because they are), but that’s not possible. Luckily everyone else is busy taking away that name from Apple (for example by naming their software like that).