There are many silly arguments here, and clearly some straight fanboy arguments. (The worst being the "imac says more professional in an office. - No one cares what computers an office has. Many of the most successful businesses in the world are littered with dell monitors; considering the incredible limitations of apple's monitor lineup, and limitations of the imac itself.)
Basically, the OP is correct. Just as the current mac pro is getting beat by 6 year old mac pros with upgrades that the new one simply can't utilize, Apple's iMac is on just as silly of a path. No one needs their desktop to be light and portable, but the general consumer enjoys it. Apple is no longer the company for "techies." It's for the general consumer. (An excellent business decision.)
Everyone knows the top of the line imac's graphics are a joke; the new (what i call "netbook") macbook line is a joke with it's single usb-c port and pathetic processor (at that price point.)
As an editor for a mid-size production company, I'd say approx. 200 out of 250 clients request a physical disc copy. Granted, not a standalone DVD, those are fairly rare now, but simply a DL physical disc with the content on it. As much as I agree that discs are dying for the general population - in the professional world they are still widely used for long-term storage and archiving. You find out quick after 100+ SSD/HDD/USB drive failures.
The bottom line is this - Apple does not cater to the professional user. It's as simple as that. Professionals need expandability/upgradeability/options. Apple used to, and they used to pride themselves on having some of the greatest computers. But they found a much larger revenue base with the general consumer, by producing "nice and shiny" products. It doesn't mean the products are bad by any means, but they're just not suitable for high end pro. users in any regard anymore.
Trust me, switching from FCP to Premiere killed me, but it's just no competition between my windows desktop and our shortly lived 2013 mac pro. And 4k after effects comps - have you tried on a maxed out nMP? Not a capable machine compared to running 980ti's on a windows desktop. I do hate windows 10, but the hardware forces me to compromise.