For the longest time bike boots didn't have any reinforcements or protectors, except for doubled leather in some spots (heels, shifter, sometimes toe cap). So, if you really don't want modern motorbike-specific boots, at least get some old style sturdy riding boots. I think they should be taller than eight inches, I'd say at least ten or better twelve. (The height and the laces rule out hiking boots. With hiking boots still being better than sneakers.) While you don't get the current standard in impact protection, you at least get the abrasion protection.
To add to the collection of gruesome anecdotes: many years ago I hit a tree while off-roading at low speed in the forest, and the impact split the heel seam, and pushed my foot into the open. Amazingly nothing was broken, and I was able to make it home. Motocross boots would have been better.