Thats defenitely true... but then you can also say this to the people that like to collect art or buy jewellery, buy oldtimers just to have fun driving them and all that stuff that makes live fun but is esenntially not needed.
I personally did not and do not plan to buy cartel coins because for me it is not worth the money... but i totally accept it if someone decides to subsidize the game by buying cc
All of what you mentioned have real value and are phyisical items. Most importantly, they are items you actually own. You dont own anything in an MMO, it is all the property of EA. Your characters and everything you have gotten on them is the property of EA. The cartel packs that you purchase and all the items you get from them are the property of EA. They can ban your account tommorow for no reason and you have no claim against them. They can shut down the servers tommorow and those items people paid good money for are gone.