I totally agree, given the many thousands of hours poured into this, and the amazing investigative powers of these CMDRs, that we should have found SOMETHING.
I'm not sure that follows either.
1) Unlike the other Frontier mysteries, the clues are extremely obscure, to the extent that it's extremely hard to tell what even
is a clue to Raxxla, and what's just completely unrelated decoration. For example, some people think the garden layout in Tourist-economy stations might be a clue; the chain of reasoning that leads to it being a clue is itself quite long and if it turns out just to be an unrelated pretty garden that some artist put together to make the station look nice that would explain why no-one who thinks it's a clue has found Raxxla. Not that the people who don't think it's a clue have found Raxxla either, of course.
Just in the active thread in recent times there are three or four separate detailed theories for how particular aspects of the game might be clues towards Raxxla; it seems quite likely that at best N-1 or N-2 of them are just looking at complete red herrings - if only we knew which ones! - and if the final answer is revealed will turn out to be on completely the wrong lines (as, it's likely, my attempt at solving it was). None of those theories, even the more detailed ones, are anywhere near the stage of suggesting "maybe Raxxla is in this system"
2) Certainly I'd agree that it's highly unlikely that the only "protection" on Raxxla is the size of the galaxy making it unlikely that anyone would go there in the first place (though, all else equal, that still has a >99.94% chance of working!). In that respect someone commenting that the system it's in had been visited might be taken as a clue that it's not intended to be amenable to brute-force searching. And there are certainly plenty of ways that could be done, just using capabilities we know that the game has had since 1.0 (hidden systems, hidden comets, lots of things that are definitely in the game but you'd
never find with just "normal" looking around and scanning)
Plenty of the theories put Raxxla (or the way to reach Raxxla, perhaps) as being within or near the bubble, so "the system has been visited" would be trivially true in that case by now in most cases (certain permit systems aside), and maybe that was the intended hint.
3) Also unlike the other Frontier mysteries, Frontier
don't want this one solved quickly. So the things which have let people solve the other ones quickly aren't there.
Again, compare with the Zurara: the initial clues given in Drew Wagar's first book actually pinned down its location
really precisely, but it wasn't found because while there were thousands of people searching, most of them were searching in a much wider region - and, in fairness, the toolsets needed to search precisely weren't really available until after it had been discovered by other means; a clue of the same precision given nowadays might be solved within a couple of weeks. And that was one where brute-force searching of systems was all that was needed.
The "someone".. not player
I don't think it's worth trying to dissect the exact wording, since that's being reported at best second-hand (and in some cases third- or fourth-) several years after the fact and is unlikely to be precisely what was said anyway.
Maybe if someone had posted about it at the time and that post could be found, it might be better on the wording, but any specific care with which the speaker constructed the statement is going to be lost by now.