From what I can see...if it exists within the game itself then I do not see how it is an exploit. If the OPs definition of exploitation is someone finding a more efficient way of doing something then you will be very very very disappointed in every game you find on the market. Some things do need to be fixed but while they are in game and the devs are not making it a priority to fix them then obviously they approve of them for now until a better system can be found. Exploitation of a game mechanic or system is not cheating and you are confusing the two if you are lumping them in together. If that is your definition of cheating then partying, mass use of leves, selling things for high prices and gouging on the MWs, continuously doing the same instance and playing for long hours doing the same thing are all exploits. They are just accepted and community/dev approved exploits. Faulting people for not going through the same painful or excruciating things you did leveling something or earning gil just means you are bitter about someone reaching the same goal faster by using another means.
So where do the other things fall (ie. botting, RMT etc.). These are cheats. Someone is using something outside the games parameters to achieve a desired result. The game does not have a built in bot, therefor anyone using a bot is cheating. RMT is no different. It is getting gil from an outside source rather than earning it through what the game offers. Banning those going outside the game to achieve their goals is fine by me. But if the game allows something to happen and you think it should change then report it as a bug. If the devs disagree then you have some options. Stop playing the game and do not recommend it to others. Continue to play your way and understand that others will play their way based on what the game allows. Build your own MMORPG and then you can make the rules.