Personally, I think it just shows how much people underestimate the Salerians, both their intelligence and their ruthlessness. I blame a decade of people reading fanfic where the citadel exists mostly to get dunked on.
It's funny really. People still panic whenever building a new phase of Liquid Tiberium Power because Nod might blow it up with a catalyst missile, but an extremely advanced civilization that's been space faring for thousands of years? That is known for their capabilities in spycraft and subterfuge? Naaaah, no waaaay they could ever steal enough Tiberium to study in a useful manner, let alone enough for it to begin replicating and allow them as much as they could ever want or need.
It's a very tiresome attitude to see endlessly bannied about.
Arguing against strawmen rather than debating with people you disagree with is generally easy so I don't see why you are tired
Let me argue some points, rather than concede to this nebulous argument that a civilization is inherently better for being around longer, otherwise we'd all be Assyrians, Romans, or Chinese because their age based advantages were insurmountable
- We know what peak ME stealth tech is, I even gave an example of it if you'd bothered to read- it's good, but it doesn't exist yet and while I'm positive ME3 has featured creeped invisibility onto Salarian special forces, that's not inherently any different than the capabilities GDI is already having to contend with.
- We've literally been talking about how insanely devalued any precious material in our economy is thanks to Tiberium. The natural consequence of our distorted economy is that others aren't going to want free trade with such a market for a number of reasons. Trade with the Council is going to be heavily regulated from both sides because the Volus are liable to explode if you ignore the economic instability posed.
- There's one way into Sol. It's a giant, enormous tuning fork that makes a colossal *ding* anytime something comes through. You can conventionally FTL in, but that explicitly produces Cherenkov radiation when the ftl field ends (though presumably less the more you decelerate). Cherenkov radiation should be very conspicuous in space.
- GDI detection schema have already had to compete against highly advanced and old alien civilizations.
- GDI is a panopticon state the likes of which doesn't really have another example in ME. I'm not going to pretend that makes us immune, but we are far more invested in counter espionage than anyone in canon ever was with the exception of the Salarians themselves. I wouldn't say the Salarians have a panopticon of their own because the Dalatrasses are in political competition (and thus by necessity spying on and withholding information from each other).
- Earth is already covered in kill-sats intended to fire on anything on the surface or breaking for orbit that they don't like. Most targets the Salarians are trying to infiltrate, presumably don't have guns lined up to fire at their surface because it's usually a poor survival strategy. .
So, we're going to have barriers with the Citadel by necessity, strong choke points that govern all access to the Tiberium, are more hardened than most Salarian targets, and will have a developed detection network using technology the Salarians are unfamiliar with. I don't doubt that the Salarians are going to see extensive success in electronic warfare, that it will be hard for us to actively hide troop/ship movements, and that they'll have some idea of what we're getting up to.
That doesn't correlate to them
physically infiltrating Earth or Venus, putting boots on the ground and harvesting a substantial amount of Tiberium and then escaping with no pursuit. That's just ignoring physics, geopolitics, and common sense in favor of a no limits fallacy. That's not how space-based stealth is shown to work in ME, that's ignoring how many space assets GDI has dedicated to creating no fly zones, and the simple paranoia of a state that *has* had to deal with espionage for the sake of the survival of it's species since it's inception. GDI doesn't get to trounce the Salarians at all things espionage, but refusing to acknowledge the Salarians aren't used to dealing with people who had to get good at espionage or be remorselessly nuked is 'tiresome'.
Edit: as for the Council having Tiberium, the Council has only explored a relatively small section of the galaxy (understandable given the Rachni) and I think we have WoG that the Scrin have been hiding from the Reapers. If you're advanced and remote enough to hide from the Reapers over multiple cycles, you are probably advanced enough to hide from the Citadel.
Edit2:
More accurately, it is a form of FTL that is very bloody obvious if anyone is looking, and has the right tools. So if you are trying to hide from people who have the right tools, it is a good idea to not use it.
This is the closest I could find to wog that the Scrin are hiding from Reapers (in describing ME FTL and why you may or may not use it as opposed to being a trap). Conveniently, it also highlights the difficulty in trying to steal our glowing death rocks.
