Why are turians the most anticipated species for MEA inclusion?

Why are Turians badass? They got their arses kicked by a bunch of hairless apes who had been spacefairing for a thousand less years than them, got their asses kicked by battletoads and were saved by a salarian engineered plague, proceeded to produce the galaxy's worst terrorist (who almost brought about the apocalypse in no small part due to also producing the universe's most pointlessly obstructionist councilor), and their entire Citadel fleet is blown to bits almost as an afterthought by a small fraction of the geth (fortunately, the hairless apes were there to save them).

ME3 shows us yet more of their "badassery" when a tiny group of human space Nazis make a mockery of turian attempt at a simple drop and grab of a bomb they planted. Unlike most other missions the player can ignore (which usually still get done, albiet with higher casualties) If Shepard doesn't do the mission, the turians fail and the bomb explodes. Half of the krogan population is taken down by turian incompetence.

Oh, and they also need Kal'Reegar and a bunch of those same "boring, fragile and useless" quarians to retake a crucial comm relay (on their own home planet of Palaven, no less) that their supposed "badassery" apparently isn't good enough for.

When you need a problem shot, ask a turian. They'll come in, miss the problem, see it's a human (or a krogan, or a geth) and lose to it, deny it exists, then ask a human (or salarian or maybe even a quarian) to solve it for them.

Turians are probably my favorite MW species aside from Humans. Could be because we seem to have so much in common. One thing about them that really stands out is their sense of duty and loyalty. Qualities I admire. Sure, it works to their detriment at times, but that actually (and ironically) humanizes them greatly.

My other two would be Asari and Salarians. Pretty much your prime Council Member species. Lets face it, they're on the council for a reason. They're some of the most capable species in the galaxy across multiple domains.

What I meant to say is not only that they deserved to get a seat, but that I find it very implausible that a race that controls the galactic economy can be made into a joke by the council.

If anything, I find it more likely that the Turians would have entered an equal partnership with them, than the idea that the Volus became a "client race".
That's like saying that the largest bank in the world is a subdivision of their security company...

It's not irrelevant. It's a big reveal in ME3.

Cerberus is just the Renegade side of controlling things. Asari are like the Paragon side. But control is what it is either way. Same goes for Liara in her private concerns.. she becomes the shadow broker. Another form of control. And I don't like either of these. Telling me they're like Cerberus doesn't do it any favors.

As for advancement --- Nobody is really advanced. That's kind of the point of Mass Effect. People turn into consumers and scavengers and lose sight of their actual potential. They can't even understand shit on the Citadel, because the Keepers block them from doing it. Javik said his people made the same mistake.. they bullshitted themselves into thinking they were masters of the universe. People are more like cows being led down an enclosure in a slaughterhouse.

Theoretically, given the option, do you honestly think that the other races of the MW galaxy wouldn't hide some Prothean goodies, if as leverage for a rainy day, or to boost their understanding of Eezo-based technology?
Hell, I find it very likely that other races actually did that - and various auto-quests in ME3 support my hypothesis.
(you get small quests to collect various Prothean artifacts that were "suddenly discovered" and in danger do to the invasion)

As for control, sorry to break it to you, but that's how global politics work today, and likely how galactic politics work in ME.
Every political move by a state today has the potential to influence large numbers of people, directly or indirectly.
And no country is innocent of that, you simply can't play the game otherwise.

The only thing the Asari are guilty of, is playing the same political game that everyone else was playing.
The fact that they mostly came ahead of everyone else if by luck and circumstances or something else, is largely irrelevant.

The Asari mostly kept galactic politics stable. Do you think that the Turians would have done a better job?
I mean they started shooting before initiating contact during a first contact scenario, just think of the implication of this kind of bullheaded attitude, and then apply on a galactic scale.