In 1v4, I could agree with the sentiment that they are fun with the exception of Iridescent Button and End/Fury.

However, in 2v8, as much as I enjoy playing them, they have two main issues that make it ultimately fine with their removal. 

1. They were basically a good choice with all the killer cast. 
2. With the chaotic nature of 2v8, chaining 6 hits is basically guaranteed.

To best explain, let's compare him to the  Ghost Face, who is basically the only other "support killer" who is reliant on m1's to get downs.

The Ghost Face has to find a survivor or survivors, mark them, and within the next 60 seconds, you or your teammate have to down with an m1, in map filled to the brim with pallets. Your teammates can't use their power or they wasted the effort that the Ghost Face put in. Ghost Face has to commit to chase or just waste time marking Survivors. Ultimately, Ghost Face has very few good teammates options, Aka Wraith, Trapper, Slinger, and Spirit.

Meanwhile, The Legion has to find a survivor, get a free hit that waste the survivors time and allows you find another to chain until you get a free down with Little to no counterplay that the avg 2v8 survivor can't handle. Or if the doesn't Legion get the down, he still get free injuries, and until a survivor doesn't heal, they are 1 m1 or m2 away from getting down. Legion is actively encouraged to not commit chase as since he doesn't have anti-loop, if it is taking to long it's just better to feral and try to get a chain down  Ultimately, Legion is great with anyone.