Yes, using the word "forced" is somewhat of an overstatement. However, here is one of the examples from the dictionary: "she was forced into early retirement". That's really not so different from what is happening here. Nobody put a gun to her head, but she was given a choice of two undesirable alternatives (early retirement or be laid off / fired) and had to pick the least undesirable one.
Consider what this looks like to someone on a PvE server who does not care for PvP. The companion is only useful for PvE, not at all for PvP. Yet, you have to do PvP to get him/it, something the player doesn't enjoy and is able to avoid completely under normal circumstances. On top of that. Bioware has stated that there will be other companions (unknown) gated behind this one. So if you choose not to do it, you are cutting yourself off from not just one companion you might like, but several in the future. That might not be a "force" but it's horrible game design any way you look at it.
Personally, I've done plenty of PvP in other games, but I don't enjoy it in SWTOR. I tried getting Pierce but I only reached five losses before I decided it wasn't fun and not worth the aggravation to myself and my team members. Yes, it was a choice.
Finally, people who say they don't care if someone else quits the game aren't thinking it through. If enough people quit, development will slow down (even more than it has) or the game could be shut down. If you like SWTOR, you don't want that to happen.