My Finder does NOT respawn. I understand what you're saying, but that's simply not the way it works (for me, anyway). Perhaps it's because I'm quitting the Finder, not Force Quitting and not using the Kill command in the Terminal. I have no idea, but I can open Activity Monitor, then quit the Finder (clicking on the desktop and hitting Command+Q) and it disappears from the Activity Monitor list and does not reappear until I click the Finder icon in the Dock to "relaunch" it.
The only thing I can think of is that I have Onyx installed and have the "Show Quit Finder" option turned on:
I get the same behavior as you. I don't have Onyx or any similar software installed. I have not set the option to have the Quit Finder menu item, which one can do from the terminal.
When you kill it the process is respawned.
Kill, using "kill" or "killall" terminal command, sends a signal to the process (SIGTERM by default). Quitting Finder via Activity Monitor appears not to work that way.