If that subplot had outweighed the main plot, I'd have the same opinion.
As is, the reapers got cheapened by the mere existence of the collectors and their motivations became way too humanized (pun intended ) to have the same presence going forward. Just a bad path for the story from that point forward imo
What do you mean main plot? That would've been the main plot. The original premise was the Reapers wipe everyone out because without fail sentient life eventually evolves to the point they use Biotics....Biotics (for whatever reason) hastens the entropy of the universe. It draws power from the universe itself, which is why that star was dying. It happens towards the end of a 50,000 year cycle, which is why that's the time frame for the Reapers return.
They were experimenting with creating new life (like the Collectors) because they were basically trying to either breed Biotics out of all life, or develop a race that could use Biotics with out those side effects. The closest they got were the Asari.
I don't know why the Collectors cheapened the Reapers, Vigil from the first game said they use other races to do their bidding. The only part for me that was
Fred.