In terms of computer monitors, broadcast standards are irrelevant.
Really??? Do some research. I guess you missed my post above where I sample a pro video supplier, a hugely popular web vendor, and a big box store.
There are vastly more 1920x1080 monitors on the market that any other rez...and I mean by far! B&H has 200 1080p models. 1440 trails way behind at 30 models. Newegg: 1,000 plus 1080p monitors, 231 at 1440, Best Buy: 496 at 1080 and a paltry 40 at 1440. Need I say more? Never a popular computer rez? Today, how about up to TEN times more popular than any other rez out there!
Although I compared only 1080 to 1440, you'll find the same overwhelming popularity of 1920x1080 monitors compared to ANY other rez. Reliable stats are hard to come by when it comes to usage because they're only tracked by a few websites and include phones, tablets, laptops, etc. Split those out and 1080 is still a big chunk on stats available from places like Steam. Include other 16:9 monitors and you're way up there, even on these biased, limited sample size stats.
Retailers do NOT stock products they don't expect to sell. 1920x1080 is five to ten times more available for purchase than any other rez...period. Now, let's think about it. Where in the world did 1920x1080 resolution and 16:9 aspect come from?
BROADCAST STANDARDS for HDTV
What is driving web consumption (and ISPs crazy due to bandwidth) these days? People watching videos, that's what. How may camcorders have 4:3 output now? How many new decent still cameras that do video don't offer 16:9 at 1080p? How many 4:3 monitors are still made compared to widescreen?
The future is here, and it is 4K, or more accurately, UHD. The former is a DCI acquisition format only, and the latter is television a BROADCAST standard. There are new UHD cameras, monitors, GPUs, and peripherals hitting the market on a weekly basis, and after CES and NAB early next year, you can triple the offerings at a minimum. Two weeks ago, one vendor I checked had 14 3840x2160 monitors. Today, they have twice that many.
There are TWO 5K displays, maybe one really because it's been said they're the same panel. No single GPU supports that rez. Then you have all of this crazy up/downscaling going on to display the image. Oh, and let's not forget driver headaches. As for all the retina hoopla, depending on screen size and viewing distance, you can get a "Retina" image from almost any rez (look at your iPhone, for example). Simple math along with a wee bit of knowledge about what the eye can see and the brain can process.
For the past few years, 1080p has driven the market, and over the next few years, 2160p will ballon faster than you'd expect. Early sales numbers say adoption is far faster than HD was. Prices for TN UHD panels are below 500 bucks now. The SST Samsung is on sale for 470 right now and there are additional 100 dollar coupons to be had if you look hard enough. The lack of content won't last long. More native UHD content is coming soon from Netflix, Amazon, Ultraflix, and more. And you can always roll your own in the meantime. Movies/TV shot in 4K/UHD then rendered out at 2K/HD look substantially better than stuff originally shot at 2K, The difference is obvious. Check out pro vid/film forums. They're salivating over 4K, and rightly so.
Bottom Line/ TLDR: Broadcast standards (resolution/aspect ratio) are not only relevant to computer monitor resolution, today, and for some time now, they determine computer monitor resolution and aspect ratio. If that isn't so, call the VP of purchasing at Newegg, B&H, and Best Buy and let them know they're making some awful decisions regarding what to stock their warehouses with.