If it's going to be more difficult to play without the companion present, then no i am not free to keep it dismissed. This is less about lore, and more about the companions acting stupid. They tend to pull stuff i am trying to avoid, they pull off my Inquisitor when i am supposed to be spec'd as a tank (yes, i turn off their taunt/threat generating abilities, but that too handicaps me and them) and yet they still pull mobs from me. They are normally more of a nuisance than they are a help.
Bioware, you need to make these companions optional. If someone wants to play without them, they should be able to. They were great for Knights of the Old Republic, it made sense to have someone with you seeing as you didn't have any recollection of your Force connection and by the time you start getting your Force abilities you have built a relationship with them, so it wouldn't make much sense to ditch them at that point. This game, however, you start out as an Apprentice and learn to be self-sufficient for the first 10 levels, and then all of a sudden you're just not strong enough to handle those big baddies on your own?