You do realize Dead Space did worse, right?
And that was opening month. They hae about a million now and developed a massive fanbase.
Uhm ...
Dead Space sold over 2 million times ...
And the opening month of ME was 30.000 copies. It did just about reach one million though, you're right.
ME was a financial disaster for EA and there was no reason at all for them to continue an unsuccessful IP.
See it this way:
You are a publisher.
You got the choice between a boring, generic CoD clone that will sell 8M+ or an innovative game that'll sell a maximum of 1M, leaving you without any profit.
Blame today's gamers, not today's publishers.