Probably because the narrative is the backbone rather than the backdrop of these games. It was the first game that teared me up after beating the final boss.

I believe this would be the opinion of the mass of people in the picture, not the single guy :)

At the time the first games were out, PMD felt like they were the only games in the Pokemon franchise that actually tried to build a world out of the lore that Game Freak made for its own monsters. Read the Pokedex entries in any of the first three generations. They're fantastic, but they don't seem to tie into the actual games themselves. A lot of them are strangely disconnected flavor text that hint at mannerisms, abilities, or feats that simply do not translate to what the mons are like in gameplay. The fine lads at Chunsoft were apparently the only ones who bothered to read that flavor text and think, "Hey, we can make something great with this." And holy shit did they ever. Several times.

This is a difficult one for me as I grew up with both (started work green leaf & GB pinball as my first Pokemon games) bit I think I agree, explorers of time/darkness was a much better game than any of the mainline Pokemon games were

Pokemon Pinball is better.