An 18 core processor sounds excessive

Who said it's for gaming? There are other purposes for a PC, of which gaming actually makes up a fairly small percent.

Commercial servers handling thousands of requests and hundreds of thousands of scripts per second.

Honestly, why would anyone need 1TB hard drive space?
Honestly, why would anyone need a 32bit processor?
Honestly, why would anyone need more than a 2 core CPU?

Time, features, power...marches on.
Software eventually catches up to the hardware.

In there current state? Most folks wouldn't use or need one. These are CPUs designed for the server space, are cut down to cannibalize a little less of that segment and focused on the high end workstation/prosumer/uber enthusiast crowd. Of these users the high end workstation crowd may actually use a chip like this to it's full extent. Not to say some prosumer/uber enthusiast won't but they will be in the minority by comparison. Gamers won't even begin to utilize that much chip for another 10 years or more. I think 8 cores will be common gaming usage in the near future as will 6 cores. Arguably even now. That will be the new mainstream market depending on chip vendor (as core counts are concerned). Users like myself who have been in the HEDT space for a long time, we will be the ones moving to 10-16 core space (depending on vendor).

Me I am thinking either a 10 core Intel chip or a 12-14 core AMD chip as far as upgrades go coming from a 6C/12T i7 3930K. For me it is about PCIe lanes from the CPU (not counting PCH) and total number of cores. I need a minimum of 40 lanes for my usage. Intel only has 44 lanes at 10+ cores and AMD has 64 lanes at 10+ cores. Below that I have to settle with 28 or 32 lanes depending on vendor or less. That and as a high end gamer/prosumer (video encode/decode mostly with a sprinkle of 3D rendering for game production/modding) I usually go with 2 more cores or more then the average high end mainstream gamer would. In my experience there are a fair number of users like myself on Tom's, though we are still a minority. Point being Intel's 18 core chip is simply a desperate attempt to show they have more of something then AMD. Ryzen T-boned Intel and Threadripper kicked them in the naughty bits to boot. Now they are left scrambling to make chips they already have designed work in the server space on the consumer front against a new product that for the most part has them beat hands down, save gaming (which is starting to change with patches/microcode/ bios updates). Just like when AMD launched AMD64 chips against Intel's Pentuim 4. Though that was a little more severe beating IMHO.

It will be another 4 years with the time it takes for chip design/development before another drastic change in performance hits, say like Intel's answer to AMD64 the Core Duo. This is a great time to be a consumer in the PC space.

Anyone looking far enough ahead or using a large enough data set will benefit for sure. I was more making the argument for the next 4-6 years for the average HEDT user.

"640K ought to be enough for anyone."

(Although it looks like the actual quote may have been, "When we set the upper limit of PC-DOS at 640K, we thought nobody would ever need that much memory.")

^ LOL those were the days.

That's one application. How well will your CUDA GPU handle a million database requests per minute? Slow, that's how.