RJ 17 said:
And it's so wrong to be an opportunist? Well... okay, maybe it is. But still, it's not unreasonable for a race to put its own interests first and foremost. Frankly, I'd find it to be pretty unrealistic for anybody to devote their best military and scientific personnel to a cause, even one as great as that, if they didn't believe they personally were going to in some way profit (beyond winning).
The Turians were already under attack, if they
didn't get the support of a race that they believed could hold their own in battle, there would have been no home for their military to return to. The Asari and Humans were in the same situations, and couldn't offer support. The Batarians were mostly wiped out. The Salarians, with the exception of the STG, are often seen as weak in battle (and even then, STG is really more about sabotage than ground warfare). So who does that really leave that's in a position to actually be okay with devoting the troops and resources, and can be trusted to fight fiercely? The Krogans.
The Krogans can also definitely have a very understandable asterisk at the end of their agreement to join up and fight. It's likely that they would take heavy casualties defending the Crucible from the Reapers, which is devastating for a race with such low birth rates. The losses that they could potentially take might potentially doom the entire species if something wasn't done about the genophage. And is it unreasonable to assume that to a Krogan, something like this might be their only chance for a real long time (or maybe ever) to get the other races to change their mind about the genophage?
The Asari were in the same position as the Turians, obligated to help their own and sparing what they could for the Crucible - except that, like the Turians, they had nothing to spare. By the time they got their chance in the narrative to make the same sort of deal the Turians made, it was too late. Upon discovery that the only hope was working together with the whole Crucible shindig that was brewing... Asari fleet, reporting in.
Salarians... ehhhh.... they're jerks. Fuck 'em.
The Quarians didn't appear to even be all that aware of the Crucible project until Shepard and the Alliance came along to request support. They just happened to already be at war with the Geth at the time. Notably, Geth that were under the direct influence of the Reapers. Note that by helping the Quarians against the Geth, you're actively removing a large war resource from the Reapers (or converting that resource to fight alongside everyone else), so it only makes sense for that situation to be resolved before devoting full support. The Quarians getting their home planet back was merely a perk.
Shepard was the deal-maker to sign everyone on, which is why I absolutely believe that Shepard was important, but the Crucible existed as the MacGuffin to make the races believe that they weren't just wasting their time and diverting resources that could have helped their own people for nothing. If the Alliance didn't have the Crucible under construction and the hope that it would save the day, I think Shepard would have gotten significantly different responses from the various races.
And really, the Crucible plan is really the only thing that gets anyone to initially give Shepard a second glance. If Hackett hadn't interrupted the Normandy's trip to the Citadel with a detour to Mars, it's likely that Shepard would have only been able to drum up light (if any) reinforcements for Earth, since everyone would have been busy setting up their own defenses.
And yeah... I've got nothing against pointless arguing. It's a slow day at my office. Just watching that clock tick, and tick, and tick away until it's time to get hammered.