The fun is in killing the bosses with friends and the loot is just something you get for being successful.
The flaw in this perspective is that if you're group wants to continue on to EC Story Mode and you're still using a Tionese weapon...you're more of a hindrance than a help.
And, fyi, getting loot is fun too.
If you want to go kill a boss with friends and don't care about look, then you can just continue to do EV Story Mode over and over and over and over...
...but if you want to progress with your friends and continue to have fun with them on new content, then you need the gear for it. Simple fact.