It may not be %1; if the shell says

    [2]+  Stopped                 units

it's %2. But it's also %+, %%, and just %, which is what the "+" after the [2] means. In my case %1 is evince zhegalkin-sm7433.pdf (Running, not Stopped), which I definitely do not want to kill.

Plenty of people open a new terminal window for every new program they want to run, but I commonly have several "jobs" in the same window, stopped or even running. Less often now that monitors are bigger, but still.

It is true this improves the bad path. It ignores desired happy path cases: downstream processes, custom debugging, graceful shutdown, preserved workspaces, and so on.