I guess I can understand not liking the inverted castle, but I find it fun, the bosses are all completely new, and it's far less repetitive and stupid than AOS' "second castle," which as I recall is exactly the same thing. (That was AOS and not HOD, right? Maybe I'm confused.)
AOS, DOS, and POR have useless weapons also, but despite that the variety is fun regardless--or at least I find it fun in SOTN. The other games, not so much. SOTN has soooo many weapons and items that you really don't ever need to use, but it's fun at least once to go through them all and see the neat little things some of them do. Same with all the items--especially the ones that cause huge naked chicks to appear on the screen. Throwing peanuts in the air and trying to catch them in your mouth to regain just a few points of health? Come on! Little details like that are so much fun! The other games have very few such tiny, useless, albeit fun details.
What are these "unnecessary things" you speak of? 'Cos I love all the weird little details and things in the game. Makes it feel far more complete than the other games.
Glitches? Yeah, there are the well-known glitches, some of which cause the progress percentage of the game to go higher--so are they really glitches, or intentional? Either way, they're fun, and I've NEVER done anything in the game that has somehow screwed me over. Seriously, when has a glitch in SOTN ever ruined your play experience? None of it gets in the way. Besides that, some of the other games have glitches also. Being able to go outside of the castle in AOS (or was that DOS)? You're not just going to look over that, are you?
What makes SOTN feel incomplete? I hope you don't say "'cos it doesn't have the ability to play Maria and the new areas like in the Saturn version," because those were all added LATER and as far as I know were not intended to be put in the original game. I've never played the Saturn version, but I hear the new areas are poorly-designed, the new sprites suck ass, and there's nothing special about the new tunes either (which, if I'm not mistaken, weren't even written by Yamane).
Yeah, the game is easy, but aside from COTM, are any of the other Metroidvanias anything more than a cakewalk? Seriously. ALL of IGA's SOTN-style Castlevanias are a breeze. Except that none of those other games have the insane challenge of a boss like Galamoth. Sure, the boss is pretty easy to get through if you have the right equipment and/or the fairy familiar healing you constantly, but he's still a pretty darn tough cookie. COTM is the only Metroidvania that really poses a consistent challenge.
As for SOTN being considered the best Castlevania, yeah I agree it doesn't quite deserve that title, but it certainly is deserving of its high praise and being considered ONE of the best. And it's so good that I honestly don't mind if somebody DOES think it's THE best, because it really IS so good. And if nothing else, arguing that any of the other Metroidvanias are superior or come even close to its brilliance and replayability is just a dead argument from the start because it's simply not true. 
The bosses may be completely new, but they're so pathetic that they can be beaten before the boss music starts(I'm looking at you, especially, Akmodan). HoD might have had that second castle, but it had a good feeling to it, and it did have huge differences later on with enemies and slight level design changes and cool and necessary items.
The other games do have useless weapons too, but not as much as SotN. What kind of joke is Red Rust and Tyrfing anyway? They weren't even worth putting in the game. The little details are also pretty nice, but I doubt there are many people that can tolerate checking them all out(or even at all probably). A lot of things just don't need to be there and instead of those things, there could have been better things that could have been necessary and probably much cooler.
The unnecessary things are most of the inventory entirely, the spells, the useless special attacks, the wolf form(all the forms could have been put to much better use), etc. There are just too many unnecessary and gimmicky things.
Sure the glitches don't really mess up the experience, but the fact that there are so many of them is part of the reason the game feels incomplete.
The game feels incomplete because a bunch of things thrown together with no purpose. It feels like an unfinished ROM hack or fangame. The game also seems a little short, and there are a lot of things that could have been put into it. It feels as rushed as PoR(maybe more, even).
All metroidvanias are a breeze, but SotN is the easiest of them all. It might just be one of the easiest games of all time. It's pathetic. It doesn't even have a hard mode. Sure it has luck mode, but the difficulty is way imbalanced. Luck mode starts off very hard, but then you're back to being a god and you're able to sweep through the game just like in normal mode. At least the hard modes in the other games are actually harder than the normal games, even if hardly any work was put into them.
The game does not deserve the praise it gets. It's not that good. Games like AoS and DoS already surpassed it in so many ways. It has horrible flaws, and after replaying it a few times, you just get sick of it to the point in which you might not want to see it anymore. It should stop getting so much praise because it is not only annoying, but the game doesn't deserve it. It's good, but not that good.