OP's is pointing out that for some reason, fnatic and EG as partner teams get direct invites, Imperial gets a direct spot after playing in the equivalent of a T3 tournament and ES gets a direct sport after playing in a NA-only tournament which is pretty much T2 competition at best. Meanwhile the closed qualifier for the event has teams like mousesports, Furia, BIG, G2, FPX and OG where only three can attend. Hardly fair is it?
"By OP's logic we should invite a consistent set of teams because each one of them used to be good at some point"
Yes, that's what they have done by having partner teams so they get a direct spot to the main event regardless of how shit they are. Case in point, the aforementioned EG and fnatic who were rank 38 and rank 29 respectively.