I like the overall darker tone of gen 1. My favorite part is going to Lavender Town, hearing the strange, somber music, entering the tower where the dead pokemon are buried, and solving the murder mystery of the ghost that haunts the tower. This wouldn't have probably gotten pass the story editors and censors today.
Being the first and most rough hewn of the generations can make gen 1 an interesting spectacle to behold. It's a grim world, barebones world that's not particularly moral with it's slot machines, peeping Tom NPCs, gym leaders training their pokemon with bull whips and several pokedex entries for pokemon that sound violent and cruel like Gyarados or Nidoqueen, others are more creepy and weird like Parasect or Jynx, and a few that are more sinister like Ninetales or Articuno.
Giovanni is a mafia don, and there's no lofty philosophy about using pokemon to change the world. You don't become friends with your rival or the champion, and are pretty much on your own in the world without regular guidance or companionship from anyone. It's about survival of the fittest. I love that Red is and should always be a silent protagonist because he comes from a lonely world with nobody to hold your hand.
Friendship does not exist as a mechanic for the player with their pokemon in the original Red and Blue games. This is not only because of the limitations of technology of the era I think, it's just not what the games were really about at that point. Very seldom are pokemon described in friendly terms. A lot of the pokedex entries when they're not saying something outright disturbing about the pokemon are just clinical observations about their native habbitat, diet and various physical attributes like their size, whiskers or the stingers on their head etc. They are more like wild animals you are training and experimenting with, and it's fascinating how the series has evolved from something so different over the years to me at least.
There are a couple of lines of dialogue in the story to the effect of, you came far because you have confidence in your pokemon, and have worked hard, but the game at its core about getting strong, and is seldom sentimental.
I'm not saying this is necessarily better or worse than the games today, but it's an entirely different beast, and I can respect gen 1 for what it is.