If it's pretty popular, it's not a niche.
Did you get confused again?

There are niches, some are obscure and some are more common, but being one of the larger niches doesn't mean it's no longer a niche. Take a look at Apple's PC market share, roughly 13% in the US. The rest are Windows. Apple isn't quite the boutique computer that it used to be, but it's still essentially a niche computer; Media creators, artists, and students tend to be the biggest consumers. Sometimes you'll see iMacs in medical offices and such, but Apple is a long way from taking the lion's share of the market away from Windows.
And also I was speaking in today's terms, I think they should introduce those things to the CURRENT iMac lines, because a lot of people need them, I'm not just saying "I need an iMac that fits ME".
If you need a 2nd HDD then get a 2nd HDD, that's what USB3 and TB ports are for. If you need an ODD then get one, the external SuperDrive functions just like the internal one, the exception being when you plug it into a Mac that came with an internal SuperDrive.
The vast majority of people no longer have a need for ODDs, so why include them? If a lot of people need them then there are alternatives, but including something that the minority wants/needs and the majority doesn't isn't something that makes business sense.
The current 27" iMac can have up to a 3TB fusion drive, that's two drives. Would you rather have two SATA3 bays with slower SSDs or a PCIe SSD and a SATA3 HDD? I'd rather have the latter, awesome speed for hot data and plenty of storage.
If you have room for a 27" iMac then you have room for a couple of external peripherals, IMO. For someone that says they're not wanting something JUST for them you sure are placing a lot of strict "requirements" on what it should have and why. The bottom line is that the current iMacs can do everything you need/want and have decent specs. The current Mac Mini does NOT have the same specs, nowhere near it. Today the iMac can effectively do more than the Mini in terms of performance. The discussion about a "Mac Mini Pro" was to address a problem that cannot be overcome with the current hardware and likely not with the refreshed model either. Your issues with the iMac are personal ones and not technical limitations. If you COULDN'T add external drives then you'd have something, but you can and that makes it a personal limitation on your part.
But, back to the Mac Mini since that's what we were talking about before you jumped into the Mac Mini section with your iMac posts...
