Except, and this is explicit from the start- the STG and Shepherd are out to destroy Saren's cure. The goal isn't 'capture the Base' or 'steal the data'- the goal was to destroy it in a cover up so the genophage wouldn't be cured. Which would hit the point about Wrex having to accept that the cure isn't what will save his people- that they have to change themselves. If Wrex is fixated on the cure, he'll die just like the Krogan failures. If Wrex is talked down, then he's demonstrating putting other priorities before the Krogan.
It's not an explicit dialogue quote, but it is the thematic conclusion and consequence of his arc- as is it's continuation into ME2. Nowhere in ME2 does Wrex say what his position on the genophage is.... but his position, and his reforms, would be entirely impossible without the genophage in effect. If Wrex wasn't pursuing reforms as a necessity, he'd be a lot more popular with the traditionalists. Except Wrex is- and he's taking that view of the necessity of reform from somewhere- and that somewhere is ME1.
Shep told Wrex that the krogans in there are just tools used by Saren and he agrees. The STG wanted to blow up the base because of the cure, I wanted to blow it up because it´s Saren´s and maybe I misunderstood but just leaving was problematic because of the heavy defenses. And the STG wouldn´t go along with a quick smash and grab, especially if the grab part is the cure data.
ME 2: The cure wasn´t on the table, Maelon researched a possible cure and killed quite a few people.
ME 3: Well yeah his powerbase are the fertile women. OTOH he doesn´t know much about this inside source. If he doesn´t react will it contact someone else? He is the obvious partner but not the only one.
Also he needs something to persuade his people to actually fight for the turians and the humans. I don´t think they would have gone along with it otherwise. Wrex is bright enough to realize that sitting on Tuchanka won´t be a viable strategy. And this is Tuchanka, people voice their displeasure with their shotguns.
Also the situation has changed, the Reapers are there. If the war lasts longer, like in prothean times, the krogans need their high birthrate. And in the probably case that the Reapers win, there is a (very) slim chance that a few krogans can hide and repopulate.
So as son as the insider contacted him, ignoring it, wasn´t an option, if someone found out his powerbase would erode in one moment.
And well ithink he relly enjoyed having the council races over a barrel. 