You can write crappy games in assembler if you like. There are plenty of horribly performing Unity games simply because it sets a lower bar for developers. Also

You can write crappy games in assembler if you like. There are plenty of horribly performing Unity games simply because it sets a lower bar for developers. Also, rather ironically, developers using the less expensive license are forced to show the Unity logo at launch which tends to associate Unity with low-budget games. There are plenty of awesome games done in Unity which you probably didn't realize they were done with Unity.