The problem with tiers, no matter what kind, is the lack of diversity.
You have absolutely no idea what you're talking about.
Hop onto PBR Wi-Fi, where there are no rules, and have fun facing the same 12 Pokemon or so, mostly one-off Legendaries like Mewtwo, Kyogre, and Darkrai. See how well your favorites stack up against them.
As said, tiers foster diversity and allow Pokemon of similar strength to compete with one another and not have to worry about the overpowered threats of higher tiers.
Players wish for more Pokemon in OU so they have to same old over and over while at the same time, not participating in UU/NU battles because they're not standard battles.
The thing about OU/standard is you can use any Pokemon from lower tiers too. Anyone (like you) who whines and moans about a "lack of diversity" and then goes on to use the same Pokemon everyone else uses only has themselves to blame.
As for no one playing UU/NU, that's simply not true. UU had a very active community in Gen 4 on Shoddy and Pokemon Online. Right now, all the tiers are still being worked out, so yeah, there are some who are waiting and seeing what happens, but the tiers are out there being tested and it's easy to find matches. Anyone who isn't able to find one just isn't trying.
What Pikachu really needs is a better movepool to counter just enough types including the likes of Gliscor and Ferrothorn.
Pikachu has a ridiculously diverse movepool for being not fully evolved. I mean, it's huge! Throw in the 4th gen TMs and the 4th and 3rd gen Move Tutor moves and it's even bigger.
And not every Pokemon needs to be able to hit every other Pokemon. That's why we have teams.
Same goes with Raichu as the light ball should at least affect the entire family.
lol. Then it makes Light Ball Pikachu pointless because then Raichu outclasses it completely.
It's the only way to retain its mascot title before being replaced by Minccino, whose evo does a decent job, or Ferrothorn.
You're delusional if you think Pikachu is in any danger of losing it's mascot status.
Pikachu will still get more appreciation due to its evo form getting more power to do well in competitive battles.
That's not what a mascot is for.
If that were true, then why do EVs, IVs, complicated battle strategies, and the Battle Frontier exist. Seem like they do give a darn about competitive play.
EVs and IVs are just part of the formula into making each and every Pokemon unique, strategy is simply something that arises out of any game pitting people against eachother, and the Frontier is for those who want a ramped up AI to face.