I don't think that's entirely true when we are talking about cross-platform play as the major stumbling block (Aspyr has multiplayer working between Mac and Mac and Mac and Linux fine). The PC - Mac xplay is more complicated and requires work on both sides.
Ideally, knowing they were doing xplatform eventually, Firaxis would've taken that account in the technical design for multiplayer (and they likely did to some degree but it's much more complicated than expected due to unforeseen issues). Ideally of course, Apple would also have been providing decent graphic cards and good API for them, but what can you do.
The overall conclusion from the discussion in the Steam Mac Thread over the past year and almost two months, I think, supports what
@bbbt says above. (Steam is the preferred way for Aspyr to communicate about Civ VI development). I must say first that this discussion has been weaved by all sorts of folks, some with game development experience, many as inquisitive and intelligent folk as we mostly find here, but definitely with a more numerous bunch of, let's just say, "misinformed and passionate" crowd, but at the end their posts also pushed forward the conversation. However, this has included a surprising number of posts from Aspyr, some more candid especially as of late. All the information shared there has many thinking, me included, that there is a problem at the source and that the expected cooperation didn't happen as expected. However, I am not removing the responsibility from Aspyr, especially, after they have finally done a sort of mea culpa by our insistence. Regardless, there is a very good chance, for us Mac users, to be looking at past the holidays to finally get the latest DLC and patch. Who knows when we will get the Expansion and that worries me. I have gotten all excited as all of you have following and commenting on this thread.
I give Aspyr props for communicating more, at least. Something Firaxis doesn't do, in my opinion, or if they do, please, let me know where to look for it. If indeed there is a cooperation and source programming issue (there are issues with Mac and Linux, of course), I echo what one poster said there: "At some point in the Civ universe, it was decided that Civ would support the Mac/Linux community. Civ could be a Windows only game, it would be successful, but Civ saw value in the Mac/Linux community. At this point, Civ had a fiduciary responsibility to its stakeholders." He ends it with a positive spin. Kudos for him.
As for me, I am excited about the Expansion and excited about Korea. Happy that I had a hunch that it would be out first civ. I have been loving the game for a log while now, but I have not pre-ordered and it is a first. I'll reconsider as I see what Aspyr and Firaxis do in the following months for Mac users. Regardless, as I have been saying as of late, the one benefit from getting updates later is that I get to see reactions and make informed decisions, as much as I feel the urge to just get them right away.