I would say that consuming dates on occasion are fine as long as it doesn't trigger cravings. I like Cliff Nectar bars myself and having one every now and then hasn't hurt my weight loss efforts.
That being said, HFCS is primarily Fructose with just a little bit of glucose in it. I believe a ratio of 80:20 is commonly used, but there are varying levels of it. The process that corn goes through to become HFCS is involved and hard to explain, but the process uses a lot of chemicals and even GM (genetically modified) enzymes. It's about as far from natural as you can get. Google how it is made if you are interested. There are articles that explain it better than I can. HFCS is also much sweeter than sugar and they use the same amounts as when sugar was used. So products taste sweeter than they used to. I think this leads to people being used to a sweeter taste.
Fructose is processed by the liver. So, when you consume it, insulin and leptin are not released into the blood stream. Both these chemicals cause your body to realize that you have eaten. So, your body doesn't recognize that it is full and theoretically you end up eating more.
Regardless, HFCS and regular sugar are empty calories. They contain no vitamins, no minerals, and no fiber. Fruit does. Fruit also contains glucose, not just fructose. The glucose and fructose are more balanced in fruit from what I understand.
The way I see it, fruit isn't the enemy because of the other things in it. Fruit does produce an insulin/leptin response in the body and the fiber in the fruit helps keep you feeling full longer. Plus fruit contains vitamins and minerals that our bodies need.
Are you following a low-GI diet? Dates may have a high GI rating, but there are other things in the bar that could lower the GI. When you are combining things at the same meal, it's hard to know what the true GI of something is.
It is also my opinion that nature knows best. Something grown on a tree seems a lot better than something made in a lab. I think the closer to the original form the better off you are too (i.e. an apple is better than 100% apple juice, the 100% juice is better than a juice drink with only 10% juice.)
I don't know if I've explained this very well, but I hope this helps.