That's because either you've not been part of the Solo/Private Group/Open mega threads or just ignored them.
The main argument for a while was Solo and Groups destroy any chance of PvP in Open. So it was suggested by myself and some others to ask FDev for an arena, so PvPers had what they wanted.
But as was suspected, those moaning did not (and do not) want a fair fight PvP mode, they just want to gank people who are not interested in PvP.
Not really. The main argument that has been here long before that sprang up is a lack of content for
all players across the board, not just PvPers.
Thinking about it though, I think this arena combat module is the kind of thing that Star Citizen has embraced too; competitions, sports etc. It makes sense to have it in the future as it adds to the immersive living breathing world we were told about in DBs diaries, and having looked at the trailer it looks like immense fun (if we can trust the trailer, but that's another story

), so yeah it looks immense fun, packed full of great backdrops, new features, and high-octane content.
It looks like its got more going for it than exploration, which in comparison is one of the most shallow skill-less game mechanics I've ever seen outside of WoW. That's my personal issue with this. This xbone module looks like it'll be extremely fun and engaging gameplay, and a lot of work has gone into it. I hope the guys who made it are put to work now on giving exploration some equally challenging fun and skill, and some content other than the same old procedural systems we've been buzzing since November 22nd last year. To me, the 1:1 scale galaxy was Elite's shining example of how awesome this game was going to be, but at the moment it feels like it was the first thing FD abandoned.
In hindsight, CQC when its released to the PC backers, will at the very least be something completely new to try while they continue to wait for the galaxy as a whole to see some meaningful content and challenge added.