The group C9 in was brutal.
The group C9 was in contained the worst #1 seed, and a completely unproven Chinese team; therefore setting C9 up to be a clear 2nd out of that group, despite coming from pool C. TSM, meanwhile, was placed into the obvious* "group of death", with TSM, SSG, and RNG all cannibalizing each other. Surprisingly, TSM's problem wasn't with the Korean team (they split with SSG), it's that they didn't beat RNG.
Essentially, what it came down to was: 1. Is TSM definitively better than either SSG or RNG? No, and no one was saying they were, everyone thought it was going to be close. or 2. Is C9 definitively better than both iMay and FW? A rookie Chinese team and a representative from the underwhelming LMS which hasn't been globally relevant in a couple years now? Sign me up for some of that.
C9 absolutely had an easier group than TSM did last year, despite being in SKT's group. Why? Because the goal is to simply place in the top 2 and make it out of the Group stage; placing first is just a bonus.
*In hindsight, Group A (ROX, CLG, G2, and ANX) was every bit as much a "group of death" as Group D was.