Well that's not true. I think that only very few quests are as great as this and I would love to have more quests that truly feel like real, coherent, enjoyable games. Because that's what in my opinion makes Zelda Classic shine. I myself aim to reach this tier of quality (and I know others who do too), but it's not easy. xD
Not easy to make something like THIS, but otherwise it's kinda easy to make something very VERY good.
Forbidden City has for example the disappearing platforms before L7. Some others and terribly many official games have it, but other quests (especially for example the otherwise kingly MMDWRDC) have it very annoying. Yet FC had them very stable and enjoyable, it's not like you want to slam your screen, it's not like if you are one pixel off, you fall. And it's the SAME for kinda all other features, see? THAT is amazing! Everything is truly enjoyable and smooth!
THAT is hard to make, yes. It probably took an impossible amount of scriptwriting and testing for Jamian to make the colour tile puzzles work in L5, so that you don't get warped away when touching a nearby tile 2-3 pixels inside, but is still not possible to walk between incorrect tiles. I just can't imagine how he could pull that coordinate checking off. So yes, making things this stable is the property of the elite.
But otherwise, as I say, it's not that much a sweat to use a free game editor that requires to preceeding education correctly and enjoyably.
During these insanely many quests I made, I was constantly paying attention how each screen matches up to the plans, what made it less or more enjoyable that expected, what modification would make it less/more enjoyable and why... ...and I keep checking that at my finished quests, too. I'm noticing patterns.
If you have some underlying vision (instead of just randomly starting up ZC... unless that was the actual underlying vision!), keep your eyes open while developing, constantly keep an eye on if it's still what you planned and is good and you avoid random quick impulse ideas and constantly beta test what you are making and then have others (pick carefully!) beta test for you, then the result is easily a very good quest!
So you say there's demand for enjoyable quests?
Most I see are ones loving joke and troll quests and are completely there and back for empty quests. A coherent, enjoyable quest is not needed to satisfy them, so they don't have demand for it. Even more, IF an enjoyable quest get released, they just whine "I get it, Plant Aria, I'm annoyed that I need to use an astounding, neverseen, never thought to be possible feature over and over". Just look back to some 2013 autumn or so, when I brought up the topic with longer posts, the trolling that ensued. It reached f word heigths. I saw very clearly that here in this forum even the concept of a coherent, enjoyable quest is far from being in demand. They just need their daily dayday and daily twelwe-is-a-dozen quest. I was there. I seen how things kept turning from the 2006 state till we reached today. I see the sigs of people, listing their favourite quests and supported projects. So demotivational contents, usually.
I know a few people who have demand for good quests, but I haven't noticed you were among them.
However, my post was specifically for Forbidden City and Jamian. This quest is objectively among the best, but I mostly talked about how much it means to me. But again, I wouldn't have gone into this big hype if there wasn't objective support behind me.
A very good quest can be lacking in one or two terms, a quest with great overworld, items, music and sfx can lack in good dungeons, a quest with good overworld and dungeons can lack in good bosses, music and sfx... But Forbidden City has all perfect, that's the big difference!
And what is even more great, it has good difficulty curve, which is a big weakness at many many quests of the late 3-4 years, be they good or bad. Link Stuck in Castlevania is amazing, a gem of the year it was released in, but I ragequitted at least 2-3 times. Legend of Amy Rose 2 was very good (it was a surprise after the first installment, to say the least...) but the impossible difficulty curve destroyed it.
But Forbidden City... races in all races... and wins!