The reason corn syrup is bad for you isn’t because it’s processed, it’s because of the fructose itself.

Something like glucose goes digestive system > bloodstream > muscles. If you don’t burn it off, you get insulin spikes that just end up making you fat rather than swole - bodybuilders take a lot of pure fast-acting carbs during/after workouts for this reason - the insulin actually promotes growth in the cells that need it. This is why decreased insulin sensitivity is a hot topic, because it stops this potentially positive process from working properly, but that’s another subject.

So eating simple carbs when you’re not using them up is bad enough. But fructose isn’t processed like that. Fructose goes digestive system > bloodstream > liver. And your liver doesn’t turn it into energy, it turns it into fat. Directly. This is the same reason alcohol gives you a ‘beer belly’ - people think that it’s the extra calories in alcohol that makes people fat, but that’s secondary. The primary reason is that alcohol itself is processed as a source of energy just like a sugar, in the liver, and again, gets turned directly into fat.