I realize that a lot of this is subjective but I was on this board when the first Civil War came out, and while it might not have been very well received, it had a level of hype and interest that this current sequel doesn't seem to come close to having. There are still people who haven't forgiven Iron Man. Love it or hate it, it had a profound effect on Marvel and it's fans.
Is it event fatigue? Have lackluster events like Original Sin and AXIS soured people on yet another Marvel event? Is it too soon after Secret Wars?
Have all the reboots, resets, rebrandings, and relaunches made it difficult to collectively get excited for a comic? Are there just less of us as comic readers in general?
Or maybe people are genuinely excited for this story and I just never noticed. Doesn't seem that way though. The response to this event seems to be a collective shrug or groan.