Compared to actual luxury items. Since is pc gaming a hobby for the rich?

Since when is gaming in general hobby for the rich?

I see you're into semantics on this one, so I'll leave you to it.

He didn't say it's for the rich just that top end machines can fall under luxury, mid level PCs are affordable and can outmatch consoles yes but the are top end machines that are pricey to build because they have the top components and customizations.

Consoles are not meant to exceed a certain price range and as luxurious as 5000-10000 would diminish their purpose. It would be a futile endeavour.

Yes, a very niche thing.

Mobile games in the style of Game of War should count. While it's free to play, the people with the most disposable money are the top tier of players.

You know you can get a high-end PC that costs in excess of a million dollars, right?
I can see how that could be misconstrued as something that is affordable for the majority.

Because luxury game consoles wouldn't make any sense from a commercial standpoint. Realistically, you couldn't expect to sell all that many consoles that cost several thousand dollars, so why would any manufacturer waste their time on something like that? The only way that would make sense if it was an already existing game console with expensive components and decorations, otherwise the thing would not get any games either.

"they lack the sophistications and convenience "

I don't know what's meant by "sophistications" in this part of your post. With that said, you can pay for a super expensive pre-built pc. If the extra minute of set up time is too much you can also pay to have someone set it up for you. You can also pay for your future upgrades if you don't want to just buy a new PC every year. Even amazon has an "expert installation for $XX" option when buying parts.

http://www.dell.com/en-us/shop/dell-desktop-computers/new-alienware-area-51-threadripper-edition/spd/alienware-area51-r3/dpcwya00b3?selectionState=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

You can buy a 400-500$ model of a console (ps4pro & xbox one x), or a cheaper one for 249$ or so (slim models).

And if your really going for the biggest and best, you can buy a 3000$ PC/TV monitor, and a 12,000$ gameing PC.

You want your own movie screen like projector and maybe 200-300" screen's theres nothing stopping you from doing so if you have enough money.

Because gaming is for child and child usually aren't rich =p jokes aside, because your extra expenditure in gaming luxury wouldn't change the experience significantly.
But there are some gold and diamond carved consoles every now and then.