Not sure of your age, and that is only relevant as I'm not sure if you were "on the scene" of computers at the time, but the CPU industry went through a similar hesitation when it came to producing CPU's that produced so much heat that they actually required a fan to air-cool them.
Once the industry, and the consumer, got over their reluctance to the idea the market never looked back and we quickly rushed towards the practical limits of conventional HSF technology.
The same thing happened with GPU's and multi-slot cooler solutions. There was an initial reluctance to "go there"...but once we did then it was fair game.
I see the 300W "boundary" as nothing more. It is an arbitrary value affixed within a spec that served a purpose in its time but that time has come and gone.
I've no doubt there were practical reasons for the 300W limitation, but because of engineering progress in developing cost-conscience solutions that address those original concerns I have no doubt the arbitrary 300W limit will be lifted.
When the DDR2 spec called for a max Vdimm of 1.95V that was with the expectation/assumption that sticks of ram would never have heat-spreaders or active cooling. Then engineering developed heatspreaders and dimm heatsinks with fans (dominator series, etc) and the arbitrary voltage limit of 1.95V no longer had a basis in engineering.
What you guys would claim to be hacks and engineering defeatism is actually the opposite. The spec limits exist because of the lack of engineering solutions to a real problem. When engineers resolve those real problems it is not a hack, it is opportunity.
There may be other downsides to the solutions which results in you personally electing to not purchase the product, but that is a personal decision and nothing more.
I personally had not problem running my Myshkin redlines at 2.2V as spec'ed by Mushkin but in violation of the Jedec DDR2 spec. Why? Because my mobo was designed for it, otherwise I wouldn't be able to set the Vdimm that high, and my PSU was designed for it.
And the existence of >300W video cards is not suddenly going to create an unforseen dynamic inside people's computer cases. People have been tri/quad sli'ing & CF'ing vcards for years, the combined heat output being well in excess of 300W.
This sort of bean-counting of the wattage/PCIe-Slot is silly arbitrary. You scale your PSU and cooling solutions accordingly if you want the product, otherwise you don't because you don't.
There's a lot of merit to what you say. Possibly we might need more than 300W for a graphics card to do the job. If so, then people (engineers/the powers that be) need to sit down and set proper guidelines.
We also need to get rid of the people who are setting the guidelines if they are truly
arbitrary, which makes no sense to me. Why would they just pick some
arbitrary number? You think they would pick a spec for reasonable well thought out reasons. These people who are, apparently, "just throwing darts at a board" to select specs, need to be replaces by people who know what they are doing.
Now, I realize they don't throw darts at a board, but that's the impression that's given by the label arbitrary. Like it's just some meaningless number that having to adhere to stifles the creative process. Now, seeing as you are an engineer, don't take this personal, please. Sometimes certain engineers just don't know how to do something within guidelines and they therefore want those guidelines removed to make their job easier, or so they don't get replaced by someone younger and brighter. Or, sometimes it's the bean counters wanting regs removed because it's cheaper. Sometimes it's managerial types, who want regs removed/changed because they feel it would help them or hurt the competition, because they can't compete within the guidelines.
Regulations on specifications are there for a reason. If they are passe and no longer apply, they need to be rewritten. Just ignoring them shouldn't be acceptable though, it can be unsafe. It certainly wouldn't be fair for one company to be operating within the specs and have their competitor just ignore them. Just like it's not fair to label someone who wants proper safety controls and products engineered to be efficient as being shortsighted. I'm not part of the, "If man were meant to fly God would have given him wings", crowd. Anarchy is not a proper solution though.