I'm not entirely clear on what the issue is. Our companions are our "pets", but they do allow us to tackle solo content which we wouldn't normally be able to. Needing on something for our "pet" actually improves our character, as an extension. The only thing I think should be changed, is to make all need rolls BOP, or only vendor for 1 credit as someone else suggested, so that anyone who NEEDS has little other incentive to NEED. Greed allows the sale, trade or auction of the item.
If they aren't BoP it doesn't matter what they vendor for.
People will need them to sell them on the GTN and make their money that way.
In any event, some people didn't get enough attention as a child and will need just to spite other players, so making them BoP and vendor for 1 credit won't help if you are unfortunate enough to encounter one o fthose people.
Additionally, items can be disassembled for parts. Maybe I only get one piece of desh out of something... The desh is still worth more than 1 credit.
Finally, making everything BoP will just increase the cries from people that make legitimate mistakes.
Most of the blues in flashpoints are BoP now, and a lot of people have posted their disagreement with that. Sure, some are only wanting a system that would allow them to farm flashpoints and sell the gear to make $$$, but sometimes people will hit a wrong button, or think that something was not what it really was.
I think that talking as a group, setting up the ground rules that work for you in advance, and then following through is the way to go.
Even if they decide on a system that you do not like, you can walk before you waste time getting started.
But if you are not willing to back-up your feelings with action, it will not matter. If you are the leader and someone breaks the rules, then maybe give them one warning, but you have to be prepared to kick them.
If you are not the leader and the smuggler or consular are needing on heavy armor that you want for an upgrade to your trooper and it was supposed to be character first, then you have to be ready to quit and make the rest of the group deal with your absence.
Yes, it will inconvenience you, and it may not prevent the rest from completing what they had started, but if you just sit there and take it, then that is entirely on you, and the next time it happens, and the next time after that, you can know that as long as you are willing to take it, there will be some people happy to give it to you.