This is a silly argument to begin with, but your facts aren't even accurate. There are 9 mg of caffeine in a Hershey's Bar. To be fair, you also have the coke amount wrong, it has 34 mg.
Citations below:
http://64.106.173.203/our-ingredients/what-we-believe/ingredient-information/ingredient-topics/caffeine-theobromine.aspx.
http://www.coca-colaproductfacts.com/en/coca-cola-products/coca-cola/.

I don't know anyone who is eating 3.7 (34/9) full size hershey's chocolate bars in one sitting, so chocolate consumption is not synonymous with drinking caffeinated soda. However, even if people were, eating that much chocolate in one sitting would seem to go against the church's stance for moderation in all things. Funny enough, I just remembered a conference talk about sweet rolls offending the spirit, https://www.lds.org/general-conference/2005/10/the-sanctity-of-the-body?lang=eng. I was a missionary at the time this talk was given, and I laughed at this talk, sweet rolls, seriously? The next week, on p-day, my companion and I had a competition to see who could eat more scoops of ice cream. We both ate 34 scoops (Cambodia, cheap ice cream, small scoops) and agreed it was a tie. We then tried to teach the gospel for 3 hours that night, needless to say, neither of us felt good enough to feel the spirit. But this is all a huge tangent all based on your false equivalency.

The point is that the church has discouraged caffeinated drinks. It has never been a part of the word of wisdom, just read the word of wisdom. But anything that can be addictive (create a physical dependency) is discouraged (here is a link for caffeine's physical dependencies: http://www.webmd.com/diet/caffeine-myths-and-facts#1). President Hinckley has stated that Also, anything that can offend the spirit should be avoided. This is council, not a hard commandment. So you can think caffeine is ok for you, some people might feel too many sweet rolls is wrong. Since this is not a hard commandment and simply council, and since the amount consumed makes a big difference too, I believe there is room for both beliefs in the church. I don't think that think selling hershey's bars and not selling coke is hypocritical.

I also have a hard time believing the reason for your desire for caffeinated drinks is really based on others fans confusion of why they aren't sold in LES (i.e. hypocrisy), or because Hershey's is sold there. You want caffeinated drinks because you enjoy them and believe that they are fine. Make arguments related to how much of a dependency they can create, rather than saying it looks bad that members drink it at home or some justification related to chocolate.

Last, you say you are worried about the image of the church, but I think the church leaders are also worried about the message they send to church members. The church is always hesitant to put a stamp of approval on anything because the minute they do some people are going to take it to an extreme. This is one reason missionaries and the brethren have so many rules. The church employs people to read everything that has the church's logo on it and ensure doctrinal correctness. If these individuals used to be authors, they are specifically told they can no longer publish anything on their own for fear that people would mistake anything they say as the will of the church.

I would not be surprised to find that caffeine is someday sold at LES, it would not bother me either. I think all food that is addictive or unhealthy should be consumed in moderation (obviously the more addictive the more rarely it could be deemed acceptable). But stamps of approval from the church take time.