Already decided you don't like the Mass Effect show? Your Loss.

Look there are lots and lots of reasons why the show could be bad sure, it could be but, to decide that at this point before it's even been written, let alone been made yet is just silly. Your only setting yourself up for disappointment because we all know that the majority of people here are still going to watch it regardless, you gain no benefit from hating it now or setting hard-line expectations as to what the show has to be.

I'm already seeing people say "It has to be the First Contact War" "It has to be Shepard's story" "It has to be something new"... no, no it doesn't. All those ideas could work, they could also fail, the execution of its creative direction will be the key as to if it works or not.

Oh but think of the canon! What canon? My trilogy timeline is different to yours as is everyone's timeline, the show is obviously going to be set in its own timeline. Bioware is already making the next Mass Effect game, it's not like they're gonna stop and say 'well we gotta wait to see what the show does'.

At the end of the day, this show could be really cool, but if you decide its bad now you won't like it regardless of its quality. Your loss I guess.