Good morning. The trouble with growing old is that you have to eat sawdust for bread, and thus if you make toast you have to eat it right away. Coffee on the other hand becomes a food group. Not just any kind of coffee, either. It has to be the good stuff made to a consistency that will allow a spoon to stand up in it without sugar. You can quote me on that.
While the Collectors thing can certainly be a backdrop, but they are not the primary motivators for any of my characters. "Loyalty missions" on the other hand, are. But once they're done, what then?
We've got other sub plots in motion at the moment that are, in my opinion, far more interesting than the Collectors.
* The Medusa
* Morgan's Family
* Naleena's problem with the Salarians - say hello to several episodes of "Alias" with an unsympathetic protagonist
* Stuff for our other characters
There is a possible solution to Deidrus: The Council temporarily reassigns him and assigns another Spectre. No not Blasto. But it would be either Asari or another Turian, or (please not) a Salarian and one of us control the character and write the plot. Perhaps the Council decided that Shepard working on the Collector issue was enough.
Perhaps the Council secretly decided to take the reaper threat seriously and a more experienced Spectre was needed for this, and this team was suitable.