You should, and you shouldn't be surprised if the answer were in the negative. If x character isn't in, why not play Melee if one thinks it's better?
I care of both gameplay and my favorite characters, and I'm seriously considering to skip this new Smash if none of my favorite characters will get in.
This because while I care of the gameplay, it's also true that the gameplay always disappointed me since Brawl, to the point that I'm still interested in the series ONLY for the characters and the several games' representation (stages, music, etc.).
If the game has no content that interests me, then I'll probably stay with Melee once again. I got both versions of Smash 4, but after some months I and my friends came back to Melee because we got bored by the gameplay so it would happen with the new Smash as well since the gameplay is similar.
I still don't have a Switch, so far Kirby Star Allies is the only game that interests me, and I don't want to buy it for only one game. Smash is the selling point of the console for me, and characters can be decisive even for getting the console.
(I played Zelda on WiiU and I didn't like it, and Mario Odyssey doesn't convince me, there are some elements that I don't like of it and I don't feel like buying it... heck, even Kirby, I'm only interested in it because they brought back Adeleine, the game seems very bland).
I don't understand it when people absolutely coat their profile with everything about their most wanted. Their profile pic, signature, and everything else. Then when they advocate for said character and suggest they're like the most deserving or something they expect you to take them seriously.
I can see where you come from, though, I don't have any problem with that honestly.
But I can see, in fact, I was used to have a different avatar before; I decided to put Adeleine in the avatar only because I'm the owner of the support thread and the OP looks better if both avatar and signature fit with the content.
Though, I have nothing against people who put their favorite character in their avatar/signature, I mean, they like the character, what's wrong with it?