I'm also a single individual instead of a team. I don't think I have to tell you about the multiplicative power a team can bring to the table.
Furthermore, I do in fact run and maintain a pack on the ATLauncher, I just don't title it 'hardcore' because it isn't. However, I offer more experiences in my pack than simply automation challenges. I offer a palette of choices for making mega-structures, if that is what you like doing. I give you a plethora of options in both magic and technology. I give you several ways of storing and sorting your goods that don't necessarily involve AE2/RS or EnderIO, although RS and EnderIO are in the 1.10.2 version of ShneekeyCraft for those who prefer that method. I have almost as much cross-mod integration as AoE, and I do it without using Minetweaker. So please, don't tell me I don't know what the heck I am talking about, because I most certainly do.
You want Hardcore? Vech's Super Hostile maps. I think several of them got updated for 1.7.10. THAT is a Hardcore experience, and entirely vanilla. Lethal challenges, puzzles, and a goal of completing the monument. I think only one person ever managed to complete Inferno Mines on Hardcore difficulty (no deaths), and that was Guude. In fact, the original inspiration for ShneekeyCraft was doing something like Super Hostile with mods, similar to the FTB concept. Only instead of purely crafting to make materials to 'feed the beast' with, it was more about heading out into dangerous areas, overcoming challenges, and instead of a 'fleecy box', you get components necessary to build things. In fact, there was a whole plot concerning being washed ashore on an island that had a rogue AI (think GlaDOS or HAL or Red Queen) kill off everyone before it, using Applied Energistics to simulate the item routing systems, with various areas having various supplies. The hydroponics section, infested with dangers, had food. The mines, with its own hazards and perils, including undetonated mining charges that could be set off if one was unwise, had ores. That sort of thing. The 'main base' had a sympathetic AI fragment, but couldn't compete against the Rogue AI until you went out and did certain things manually. Finding hidden 'data cores' (16k storage disks with valuables stored within) were bonus objectives. It used a combination of mods and command blocks to provide a more complete experience.
However, I fail utterly as a map-maker, so instead I simply released a lightweight interconnected pack, ShneekeyCraft. Designed originally as 'introduction to modded minecraft back in the 1.5 era'. And 1.12.1 release, when it comes out, is going back to those roots, using FTBUtils to make a guide to explain to new players How To Modded Minecraft. Introducing basic concepts, where good places to start might be, what this pack offers... that sort of thing. Which is why, in addition to delays due to Hurricane and this thing called Work, Significant Other, and Kiddo, the pack is still in alphadev. I'm trying to strike a delicate balance between presenting information and being a railroad tutorial, I'm aiming at the former not the latter, and that's not the easiest thing to do.
Staring at an interface for hours? That's not challenging, that's not hardcore, that's boring. And that's 95% of what AoE offers. So I stand by my position that while I applaud the mod interconnectivity, it being the first major pack that many people play that actually cares about it instead of just tossing in all the mods into a big kitchen sink and calling it a day like FTB has been known to do, and I absolutely approve of it as a superior (if grindy) pack in general... I don't consider it 'hardcore'.
To do an actual 'hardcore' pack, I would need at least one partner who is good at map design, who is on the same page with me so we can work together, and who has a few months to devote to the project. Or I would need to simply bite the bullet and lrn2map, which is going to take several months before I can even start the process. Either way, I doubt I would have the real life resources to devote to such a project. Which is a shame... one of those checkboxes left blank, I suppose.