DISCLAIMER: contrarian response follows.
Why does it need to be any closer?
Really.
When I pull into a slip I spend time setting dock lines first before I shut off the engine. In my home slip I never have to get off the boat. I leave the lines on the dock and pick them up with a boat hook. When visiting, I leave the engine on until I have at least the bow & stern breast lines attached to the dock, then get back on the boat, and sometimes even set the spring line before I shut down. When I anchor, the engine runs until I'm set with the anchoring job.
In none of those cases does it matter a whit where the shutoff cable is. And mine's right at the cockpit panel. For all it matters to me, it could just as well be as the OP described without any issue.
I'd be interested to learn why folks think it needs to be closer. After all, I've only had this boat for 25 years.