It's because they lack the personal qualities, and in game qualities necessary to beat teams like Astralis. They are mostly young players, with very mellow personalities, which has seemed to result in them feeling down, having issues, and losing faith in themselves too often. Mentally, they need someone to help them, or a new player with a bigger personality.
In-game wise, mousesports with styko as it stands was, and never will be enough to overcome and achieve what they all want. The team is just not quite up to par, and is just slightly too weak to take down the giants of the scene often. They will need to make a PROPER roster change in order to get over this hump. The players had woken up to it, and made the right decision to remove styko, but adding Snax was a failure, and has now installed fear and doubt into mousesports making such a move again in the near future, which is highly unfortunate.