Well of course all of them are easy, but the point is that Kanto having low leveled Pokemon still is really wtf, and the lack of a VS Seeker really hurts it. The distribution is pretty terrible and having most of the decent Gen 2 Pokemon not even show up in Johto was stupid. I love HG/SS but liked said earlier in the topic, it didn't address any of the cons that the original had. Could have been the most refined Pokemon experience.
BW2 has awesome Pokemon distibution and a pretty fast pace, though admittedly I think it was released too close when people were already tired of DS games by BW's release.
Anyway, all these lists are silly without Gen 1 being at the top (with glitches). I'd put it like middle otherwise, but with glitches the game is hilariously broken and fun.
Kanto's the post-game, though. The fact the level distribution there is poor is pretty acceptable when HG/SS already has the most post-game content of any games in the series as it is. Obviously, I'd have liked them to be better, but I struggle to see how this reduces HG/SS from top-tier.
I actually liked that some Gen2 Pokemon were restricted to the postgame as well. Johto felt like a 'fluid' sequel to Kanto - it followed established rules about what is common and what you encounter in a given area, while mixing it up just a little. When new Pokemon were introduced, there was normally a reason why - e.g., Sentret and Hoothoot rely on the new Day/Night mechanics, which provides a coherent reason for why you couldn't find them in RBY (no Day/Night), the baby Pokemon require breeding, which again you couldn't do, etc. Johto's Pokemon distribution just made in-universe sense, if you see what I mean - it reuses the base 'rules' of what Pokemon you find where from Kanto, but with extra bells and whistles. I liked it more than say, Hoenn's distribution. It never made in-universe sense to me that despite Hoenn being within easy flying distance from Johto and Kanto, you would never see Pidgey there, for example. I bought it for BW because of the sheer distance between Unova and the original four regions, but DPPt and RSE had distributions I wasn't really fond of.