Whether its a quality issue, or people are getting tired of its particular brand of zombie survival, DayZ appears to have seen a sharp, rapid drop in its player base over the last few months.
A thread over on Reddit points out the waning popularity of DayZ, based on its reported player base on Steam Charts. At one stage the game was constantly in Steam's top 10, though it's been some time since it occupied this lofty space.
Going by Steam Charts, DayZ had respectable numbers up until March of this year, after which it saw a sharp fall, going from 29,000 peak players to 13,000 in May. For a game that has had a relatively stable base (including the expected decline from release) since early 2014, it's quite a dramatic change.
Discussion on DayZ's subreddit suggests a lack of new content and poor performance are to blame, with the biggest drops coinciding with patches 0.54 and 0.55.
We've just had a bunch of big PC releases recently -- GTA V and The Witcher 3 being the standouts -- which could certainly have eroded DayZ's player base. Perhaps it will recover in time... but if it doesn't, it could be the first signs that we're starting to grow bored of open-world zombie games.