Honestly there aren't any series with over 1000 characters that each get as many animations and details. Expecting them to maintain and renew all Pokemon for every game is too much when they could spend that effort making new content instead.
I think the haters are way overblowing things.
What kept me coming back to these games - in spite of their serious lack of growth and innovation - was the comfort of knowing that all existing pokemon would still be available and viable. I made a mental list of ten of my favorite pokemon before seeing the cut list; only one of them is still in Sw/Sh. It's weird and rather depressing to now be faced with the very real possibility of hundreds of familiar little critters being permanently put out to pasture.
Sw/Sh would need to bring some major innovations / improvements to the table in order to compensate for this, and based on what I've heard so far, Breath of the Pokewild won't reach that bar by a long shot. Add onto that the larger ratio of Gen5 and Gen6 'mons making the cut due to the director's personal preference (it bears repeating that the infamous duo of Vanilluxe and Garbodarbodarbodor made it in over Bulbasaur and Squirtle), and the whole situation honestly stinks. It took seeing the cut list for it to finally sink in, but Dexit has genuinely soured my mood towards both Sw/Sh and the future of the franchise.
Name the ten Pokemon. Are they starters or legendaries? If so - no shit they were cut. Are your favorites stuff like Luvdisc and Nosepass?