Not even in Generation V and on? That's just being pessimistic.
What do those two sentences have to do with each other?
Do you even know how difficult it is to obtain all of the Generation II Legendaries and starters in Generation III? And do you know that it's not that easy to obtain many previous-Generation Pokémon in only Diamond and Pearl either? And there's no known way to trade back to Generation III from Generation IV.
And what better idea for a future game to be a GENERATION II REMAKE?
If you're going to pick my paragraph apart, so be it. The second sentence was backed by the third.
Honestly, I don't care how *difficult* it is for you to capture all the Pokemon. I had coloseum and thus didn't *bother* getting any of the legendary 2nd gen Pokemon in FRLG. Not that it matters, through XD and Coloseum, I have Raikou, Entei and Suicune; Ho-Oh and Lugia. I went to the JAA and got Celebi. I have all the unobtainable Pokemon.
I'm not one to play a game strictly for collecting (I've yet to complete a Pokedex), but honestly, it doesn't matter. I have what I want, and what I had was obtainable.
Nintendo wants to make money. That is its primary goal. The reason for splitting RSE and FRLG was two-fold; to force people to use Pokemon outside what they were used to, and to force people to buy more merchandise. This isn't possible with DP because DP already offers a near-full compliment of Pokemon. There is no possible way to accent it in a positive way (besides the move tutors that the third installment of the fourth gen will offer).
If you look at the progression of availible Pokemon, fourth gen is to third gen as second gen is to first gen. Look at the games. GSC had the near full compliment of Pokemon in it, using RBY just to collect a remaining 10% or so. Likewise, DP has about 90% of all availible Pokemon on it, the rest gained through the (more expansive) third gen.
So what does that mean? It means, simply put, that a GSC is implausible merely because it wouldn't offer anything besides nostalgia. FRLG succeeded there because not only was it the beginning, but it offered another ~170 Pokemon for use, the rest coming from Emerald. A second gen remake has no such advantage. There would be no DP Pokemon; heck, there wouldn't be any RSE Pokemon. You'd drop from over 400 Pokemon in a game to just 200, and with no real rationale behind it.
The best idea, fyi, would be the third installment and events, just as it has always been.
For those tl;dr: A GSC remake is implausible because it would be a massive step back.
Yellow and Crystal, and Emerald by association, are third installment games. They are part of the Pokemon tradition. FRLG are anomalities, ones that shouldn't be expected.
I honestly don't see why people want to take such a step back instead of progressing forward. If Pokemon repeats in this manner, you'll have a remake of an old game alongside every new generation. This will be ultimately self-destructive as people will begin to question Game Freak's (and Nintendo by association) creativity and skill.