Clearly you haven't played DP without Platinum to say that. Electivire never was top-tier, but to say it was "never good"?
The real overhype here is the "Electivire was overhyped" one.
With Electivire, it's not actually as bad as most people say, but originally, there was a lot of hype around Electivire (look at my join date), and it wasn't quite that good, which I think annoyed a lot of people, so some people started making out that Electivire was actually the worst Pokemon in existance, completely useless, blah blah blah, in an attempt to combat the overratedness of it (some people have admitted to doing that, if you look at past threads on this).
The result now is that Electivire is probably now underrated, if anything, that n00bs come along saying "Electivire sucks", because all the top players say that constantly, so the n00bs think if they say it too it makes them look cool and skilled at Pokemon.
But I think the saddest thing is that 4 years later people are still repeating "Electivire sucks", even though people stopped going on about its type coverage years ago. Kind of sad really. I think everybody gets it now!