Well, you know the saying about opinions.
Right because other than the performance issues, this game actually got amazing reviews about its storyline and gameplay? Oh wait, the reviewers actually ignored the performance issues and bugs and gave the game a fair shot by looking at the gameplay and storyline -- which were rubbish:
"Those issues can undoubtedly be fixed by a patch somewhere down the road,
but that patch seems unlikely to fix Unity's biggest flaw: it's just not very much fun. For all its hugeness and graphical splendor,
Unity is starved for excitement. It's much too concerned with a story that feels confused by itself, wasting potentially interesting allies and antagonists in much the same way that it wastes the rich, violent history of its time period. The most interesting missions in the game come far too late, representing glimpses of a better game than the one you just spent hours playing. Even as a tech demonstration, Unity fails to captivate outside of its stunning art design."
http://www.giantbomb.com/reviews/assassins-creed-unity-review/1900-686/
"As I write this, Assassins Creed: Unity is a bugfest, but technical problems, however annoying, can and probably will be fixed.
It is not cracks in textures that it is the most worrying thing about Unity, but the cracks in game design and writing." -
Riot Pixels
"An amazingly beautiful and
dull adventure that takes the series well established elements and let's you repeat then yet again in an uninspired infinity. Not even hardcore fans should make excuses for this barely done game of bugs and
routine work. Actually they should be the most upset.
With Unity the series has gone from it's best to maybe it's worst."~ Level7
"Mild improvements in traversal and combat are quickly overwhelmed by the creaking systems onto which they have been grafted. Revolutionary Paris is one of the most beautifully realised environments in a series that has had its fair share of them,
but the game you play doesn't really do it justice." ~
EuroGamer
"Unitys metanarrative turns something specific into something simple, general, a clean way to experience a
false history devoid of any attempt to explore what made the era so significant."
Kill Screen
"Despite the title, Unity is all over the place, a jack-of-all-trades that seems almost determined
not to master any of its fundamental components" ~
Slant Magazine
GameSpot called it one of the most disappointing games of 2014 and it wasn't even a contender for any platform's genre/game of the year.
If one wants to waste time, Evolve is a better way to do that.