What's stopping you from being excited at this game?

Well, I think there are three main things that have prevented me from getting 100% hyped...though I am still looking forward to this game more than probably any other game right now.

1.) Since the Wii U version was cancelled, I was forced to change my pledge to the Switch version. But...I'm kind of waiting out the Switch. I have heard reports that it may get a revision, and the recent delay of Metroid Prime 4 makes me cautious of adopting too early. (I got a Wii U when it was originally stated that Breath of the Wild would be a Wii U exclusive; as we all know now, it wasn't.) And PS4 and other current-gen consoles are so close to the end of their life, I'm not eager to jump on board them, either. So, basically when the game comes out, I likely won't be playing it for a while because of the stance of cancelling the Wii U version.

2.) I have mixed feelings about IGA's tenure with Castlevania. I appreciate what he did, and he kept the series going, but whether it was because of his philosophies or Konami's meddling, the series got stuck in a rut. I don't think some of the action-platforming strengths of older Castlevania titles were ever fully utilized in his titles, and some of the more interesting, more ambitious and unique pre-IGA experiments like Castlevania 64 and Legacy of Darkness were never properly followed up on and further evolved in 3D, which eventually brought us to the frustrating moment of desperation that became Lords of Shadow as IGA was sidelined. Because of this, I have to temper my expectations for Bloodstained, because I know it's likely not going to be the full evolution of Castlevania I wished for, yet I also know it's probably going to be the closest thing in this current environment of game development. If we're talking 2D or 2.5D (and not 3D), I think ideally I'd want a strong, refined mix of Castlevania II: Simon's Quest (i.e. death pits, questing beyond simple transactions) and Symphony of the Night, with more variable geometry/destructible areas in the vein of Castlevania III and IV.  To IGA's credit, I felt the enemy placement and jumping sections in the demo were better than most of the recent Metroidvania IGA titles I played. (Order of Ecclesia, for better or worse, slipped through the cracks for me after I was underwhelmed by Dawn of Sorrow and Portrait of Ruin, so I can't speak for it too well one way or the other. I will get around to playing it, but I'm not in a hurry to do so right now.) And moreover, IGA and Co. actually had some pieces of the Bloodstained environment dynamically changing, like falling masts for platforms and falling chandeliers and lights turning on. And the rotating effect going into the castle warmed my heart. I hope those aren't just rare things. I would have loved the flooding on the ship to have sealed off an inconsequential area that you had to race through to prevent drowning. The questing being about defeating so many of one foe or getting a certain dropped item for cash aren't too encouraging, on the other hand.

3.) The overall art direction of Bloodstained hasn't had a strong focal-point identity for me so far from what we've seen in terms of characters and enemies. But then, we've only seen tiny slices. Because of this, I'm not sure I fully love the art direction. It's closer than most games to my ideal, though. And I must say, the fixes already made to character models are helping some.

All of this said, I really enjoyed being able to participate in the demo, and how the devs have responded to the feedback. I think the game will be vastly improved from the process. If all the game is is the demo, then it'll probably be a 7/10-type game for me. But if it's refined from that point and the rest of the castle lives up to the hype, it should at least get into the 9/10-rating area for me. I went into extreme detail over what I thought was working and what could be helped here, if you're interested.

The lack of interesting news and the negativity we have been dealing with recently

To maintain interest, I actually replay the old games. My favorites are Aria of Sorrow, Dawn of Sorrow, Portrait of Ruin, and of course Symphony of the Night. I usually wait at least a month or two in between games before starting up again. It's long enough that I forgot a few things and I am intrigued once more.

I played Chasm. Because of the level design, I never had any interest in playing the game a second time. But I had no regrets supporting the indie developer. I also tried Salt and Sanctuary...for the life of me I can't get interested in that game ever. I am more pissed about spending money on that game than losing money for this one (hopefully that doesn't happen!).

Nothing. Absolutely nothing.

My positivity for Bloodstained from 2015 to now has been nothing less than unwavering

It'll be great and I think it will be cornerstone of a new IP that will only get better.

I had thought about this too. One of the best things about the Castlevania franchise was the enemy design based on monsters and characters we are familiar with from stories as a kid (same kind of monsters you mentioned). I just remember playing Chasm and the enemies didn't really vibe with me; it got to a point where I was just swinging the sword without the appreciation of the enemy I was swinging at. But lets reserve judgement when the game is released. 

Just speaking for myself, all the monsters felt familiar to me, regardless of what their origin stories are. It's because these demons and monsters usually appeared in some film, show, or book I read growing up. The enemies from other games (like Chasm), didn't give the same sense of familiarity, hence it wasn't as engaging for me.