I would say it is rather obvious that Battle forums are not what they used to be so I will not make my list and describe the ten things that are having the largest affect on the Battle forums. No real order.
 

1. Troll and Fanboys: This is an obvious threat and their are some trolls who we do not even realize are trolls yet we continue to feed them. People go off on rant arguing with Fanboys and Trolls and all you are doing is destroying a thread and eating up all the conversation time. If they are simply ignored and go un mocked or debated with forums will go by allot smoother
2. Character Worship: A character will begin to gain an almost mythology and legend to his or herself where they are completely unbeatable and nigh god status on the Vine. This causes people who do not know the character only the legends and hype to just randomly assume every fight they are in with no facts to back it up thus creating a poor debate.
3. Viner Worship: Though I respect and admire my fellow Viners with these grade and rate a Viner threads Viners are put on plateau of God Hood to the point where no one questions them anymore. They just assume they are all knowing and always right. They will not even make a case for the other part and just follow like sheep. Elite Viners do not know everything.
4. Not Reading The Thread: People will jump into a thread and randomly post their opinions without reading anything that was posted before hand. They wind up looking dumb if there answer was factual disproved and it will also lead to disorder and name calling which is not needed. As well they will keep randomly posting their opinion not even bothering to look back at others and not even caring that they have been disproving ignorance is bliss.
5. Unnecessary Hostility: This travels through the rank from Elites to Trolls. People on the site will just be very aggressive and rude about their opinions and what other people think. If someone is wrong their is no need to say nasty things to them it can easily be solved in a friendly manner aggressive tones make our site look unintelligent. Also if there is and opinion based question and you have a different opinion than someone else shut up. Do not make your self a jack ass and go after someone for their beliefs.
6. Vine Gangs: Viners will join almost little clubs allot of the time this can be good I have been in a couple of these tight friend clicks before and it can be fun healthy friend ship talking in PMs or even on other communications services. But sometimes these just create disorder of people with all the same beliefs who will flood and always back their friend up even if said friend is wrong and they know it.
7. Company Stereotypes: Viners will base a character after stereotypes of that character respective Universe, This tends to happen more or so to characters in the DCU and it's multiverse allot of times to win debates Viners will rely on calling out that DC is to over powered or is filled with plot holes and it is no fair instead of creating a feasible argument or respectively declining 
8. Never Know When To Quit: I do not know if it is Ego or delusion but a big problem is that people do not know how to respectably surrender and congratulate the other Viner. Even when all the tides are turned and it is a man vs an army people will still say they are right as if admitting you are wrong is a crime worthy of death. I feel if people were more comfortable accepting defeat it would improve the over all "Zen" of the Forums and make life allot easier.
9. Anti-Worship: Their are characters who are very popular and when something is popular people for some reason tend to hate it maybe in an attempt to be cool. But this just becomes a problem for us all when for example popular characters who tend to be victorious allot get a allot of heat and people just try to come up with ways for them to lose or join a thread just to bash the characters instead of even debating and that is just plain immature.
10. Recycling Characters: There is a world of untouched characters and debates we could enter into but people always want to do the same guys over and over and over again. When some one trys something new it is usually turned away faster than an old glass of milk. Now some people may say "Well we do not know of that character." Well OP how about adding a little info and refrences in your thread you know to help your viners learn about new characters and have new super fun debates!