I disagree strongly. It is only "broken" because the "Arduino people" broke it. If they hadn't wasted time breaking it we would have a better forum.
Well, I'm not so sure. There is
the matter of configuration, but they are using a stock
forum/ BBS package, not something of their own creation. Whoever wrote
the said package for some quite insane reason decided to incorporate this "redirect" system because they were a smart-arse and thought that was some "feature" of HTML which for some reason impressed them (this would not be the first time such a thing has happened), but was simply not sufficiently competent to know how
to do it, so should not have done it in the first place.
The fact that it "mostly" functions and is - as has been said - used in various other places with apparent
success, clearly led the present operators to presume
that it was "fit for purpose". Not an unreasonable expectation as such and I cannot entirely criticise them for persisting with it . You might (well) ask whether they have adequately researched the obvious problem and whether there is
a known and documented configuration situation causing it to misbehave which could
be remedied, but I can see that the option of porting a whole forum database to another, more reliable package would
be simply too daunting.