You have the correct attitude. Six months ago, who would have guessed that we would get Ridley and Castlevania content? Every single character returning? Ridley and K. Rool were the two most wanted characters for over 10 years. The roster's distribution so far is evenly spread across the past and the present (three made their debut in the 1980's, two in 1990's, one in the 2000s, three in 2010's). Even among the traditional whines ("we need more villains and females"), this roster has given us a lot. We got four female newcomers so far (Inkling, Isabelle, Daisy, and Dark Samus) and three villains so far (Ridley, K. Rool, and Dark Samus), which for females is more than every Smash game except for 4 and for villains more than every game except maybe Brawl (depends on which of Wario, Wolf, Meta Knight, and King Dedede you count as villains or not).
There is really no single character for anyone to point to as an "injustice" for he/she/it not making the base roster (there are no characters left that were on par with Ridley and K. Rool in terms of requests, and no cuts this time for people to be upset about). Sure there are characters that definitely deserved to be in, but there is no consensus this time as there was with Melee, Brawl, and Smash 4. We also flat out know most likely DLC is coming, so the bitterness about the base roster possibly having very few newcomers left does not make much sense (you will simply have to wait past release date for prospective additional newcomers).
What is the issue with this roster aside from there being less newcomers in comparison to Smash 4 and Brawl (which Sakurai warned us about since E3)?
This is easily the best roster to date. We even got many surprises with this roster. Who saw Ridley coming after Sakurai said he was too big? Who saw Simon Belmont coming (before Vergeben)? Who saw Daisy coming over Toad, Captain Toad, Waluigi, Paper Mario, and Geno? Who saw Dark Samus coming (before echoes were known)? Who saw Chrom coming after Smash 4 mocked the character multiple times (again before echoes were unveiled)? Who saw Richter coming even after Simon was "leaked"?
We got a very good mix of characters people wanted and pleasant surprises. For a roster that might have less newcomers than Melee, Brawl, and Smash 4, Sakurai could very well have done the best he could have done with the time and slots he had available.