I am not entirely sure if that was directed at me, probably not (as I didn't insinuate that he wouldn't be considered). However, your last notion really bothered me. Sakurai had "no reason" to consider Metroid's main antagonist? I don't agree with that sentiment, especially as he had somewhat of a following after the Melee opening fiasco. I am not saying that he needed to be at the top of Sakurai's mind, but at the very least, he should have been considered.
It wasn't.
It was directed at the statement Kana made.
And aside from that, no, Sakurai had no reason to consider him when you actually think about it from a logical standpoint.
Ridley
did not have a huge following (especially not in Japan) until Brawl was shown off at E3 2006, a year after Sakurai
already decided on the characters. He may have had
some following in the US, but it wasn't anything comparable to now.
It also wouldn't be until just recently (about a year before characters were being decided) that Ridley's status as more than just a recurring boss would be known, as the backstory about him orphaning Samus and their deep history did not come to light until Zero Mission's release, or more specifically, the prequel e-manga that would come with it.
And, sad as it may be, given that Ridley generally was portrayed as a large flying monster since Prime, it is highly probable that Ridley wasn't given much thought in regards to feasibility.
So, lack of huge following, perceived infeasibility, and not terribly notable until just recently? Add to the fact that Sakurai pretty much said there was no consideration for him to be playable in Brawl, and it's pretty glaring
why he wouldn't have been.
But......now is different. Ridley's got a grander following now that's even notable to the general Japanese, Sakurai is aware he is wanted and now has the seeds of gameplay concept planted in his head, and Ridley is in damn near every Metroid title now in some form. It's
now that Ridley has his big chance.
On another note,
You bring up the "Melee opening fiasco"; are you referring to the E3 2001 showing of Melee? I do not recall Sakurai being present at the event, and considering that people were cheering when Samus showed up in the general gameplay portion of the trailer, it could easily have been taken as "Samus is a
really popular character in America" and no thoughts about how America liked Ridley popped up since Samus was
also present during the Ridley scene of the opening portion.