I've been a fan of Pokémon since 1999 when it exploded in the USA. That said, I have an endless number of issues with the way Pokémon has been handled. Dropping the national dex doesn't even make the list considering the number things they could do better.
The core of it is that they've never done anything to develop Pokémon beyond what it was in 1999, except for adding more Pokémon. The core games are tired and samey, and I doubt they'll change. The anime is actually just bad. Just really really bad. And they won't change it no matter how much it screams for change.
Sure, you can still park a six-year-old in front of episodes of Pokémon, but you can also park a six-year-old in front of something good. A six-year-old will enjoy episodes from the 80's/90's Teenage Mutant Ninja Turtles show, but the 2012 show is just obviously better all around, and still appeals to the same six-year-olds. TMNT has its own issues, but at least every TV iteration isn't identical. Does anybody still care about Ash Ketchum? Head cannon about why he stays ten forever is more interesting than the real cannon.
The problem with Pokémon is that they want it to stay Charmander forever. They won't let it evolve even after over 20 years. Sure, it's a kids' franchise, but that's not what's holding them back. I could literally pitch ideas for Pokémon games, shows, and movies all day. Kid friendly too. The Pokémon world is super rich, they just won't use it.
So yeah, my issue with Sword and Shield is not that they are doing anything differently, it's that they're probably just doing everything the same again with a new coat of paint. I guess some people just want the same thing over and over. Giant Snorlax yawn.
The problem is that Game Freak has been selling the same game for so long that they completely forgot how they succeeded in the first place. Game Freak believes that their brand name as a game developer carries more weight than the Pokémon franchise itself which is far from the truth. The fact that they're looking into new intellectual properties (IP's) with "Town" being a more polished JRPG on the Nintendo Switch than Pokémon Sword & Shield is completely ridiculous although I can't honestly blame them for wanting to try something different after being burnt out on the same IP for so long. Still that doesn't excuse the millions of Pokémon players whose lives have changed because of it. They deserve a much better product than what they've been getting in recent years considering how bad Sun & Moon and Ultra Sun & Moon were.
Game Freak is losing influence within the Pokémon Company due to the success of Pokémon GO as well as their newfound focus on mobile gaming and it's only going to continue to get worse the more they choose to ignore the fans who've been with them since the very beginning. The sad truth of the matter is that Game Freak could go out of business as a game developer and the Pokémon franchise would be completely unaffected by it whatsoever thanks to the new mobile games on Android and iOS, the Trading Card Game / Online Card Game, the toys / merchandise, as well as the Anime / Manga. If those other parts of the franchise completely fail then they'll have no one to look back on except the company that got them there in the first place: Game Freak. Because that's where it all started back in 1995.
The real reason why people have been making such a big deal about the removal of the National Dex is in part due to this new online cloud based service known as Pokémon HOME where you can transfer Pokémon from the old games onto it. However starting with Sword & Shield you can only transfer those Pokémon onto the new main series games If they're already registered in that region's PokéDex. This means that any Pokémon not found in that region's PokéDex will be stuck on Pokémon HOME until the next entry to the main series titles gets released since it's a one way trip. What's even worse is that you can't battle or trade online with friends through Pokémon HOME since it all has to be on Sword & Shield or on future main series titles. In other words you're paying a $60 subscription fee to transfer Pokémon with each new game release.