Something I haven't thought about, but that's a good question! The only thing remotely vertical like that are ladders, fences, and vines and just the couple cobblestone wall types. I agree that more wall styles could be added.
No there shouldnt be any problems as to why we dont have this lol. Should be the same amount of work as it took to make observer blocks.
My biggest question is why do updates take so long for such small things? Like water being able to go over a half slab or a new colored button. By the time they finish making this stuff another game has made a car with changeable stations, hydraulics, tintable windows, changeable body kits, and also have made flying helicopters with rockets and miniguns, and also have 50 new brandnew types of clothes, and also have made a brand new story mode, and also have increased the graphics of their game by alot all in just 1 game.
Then minecraft comes out with an update that now has 6 NEW COLORED BUTTONS..............
Nope, it's good business. Minecraft has been a popular game for almost 10 years now. A big part of that is pacing themselves for how often they add new content, if they just dumped everything in everyone could ever want within a year, either they would run out of updates to do, or they would over-do the content add ins. This would either ruin the game, or make people bored of the game more quickly.
If minecraft dumped everything into the game within a year and couldnt find anything to add to the game after that (highly impossible), the game would be absolute perfection. Especially if some parts of this new content cost a little bit of money then there would be little to no need to update the game anymore since players wont even be up to date since they have to purchase a few things to get caught up.
And its not like theyre alone, they have the entire minecraft community (well, the older ones maybe) to help them with ideas and content should they run out of ideas making it close to impossible for this game to ever suffer from being over loaded with new content. Yes you should give players some time to absorb a new update you released but a good 4 to 6months is fine not a full flipping year and a half just to have water go over half slabs, thats just depressing....
There is a game called survival craft that would probably murder minecraft, they have a wholleeeee lot. It was because of that game that i decided to play minecraft thinking 1 day it would be better than survival craft since mc is so popular lol. I was wrong lol, they have so much content now that my sister showed me a while ago that it makes minecraft look like it just came out yesterday xD
I guess everyone wants different things but I think there is a danger that too much could be added just for the sake of it without actually enhancing the game. When you say "dump everything into the game" what is everything? The reason things are added gradually is so that the devs can see what is needed, what will work/enhance what's there already with upsetting balance. Otherwise you end up with a total mess.
This is a LATE reply but i wanted say that i understand what you mean ConArt, but i dont think its a good enough excuse for some things like
vertical half slabs, dye water different colors, colored lights, purchasable player animations or emotes, soldier villagers, combining purchased texture packs, glass without a forced frame around every glass block, more special enchantments like a sword that freezes enemies when hit, etc..
This is not to say im not pleased with game. Its charm is taking me over, and the updates are pleasant when they get here, its just some things im sure they know we want and they cant go wrong giving those things to us and adjusting it if things go wrong.
On the other hand, cheers for getting one of the things that was hoped for! More walls!!!