It is impossible for anyone on this forum to know what specifications for any camera or lens can be attributed to market research and what specifications are attributable to engineering or financial decisions.
While I generally fall into the camp that argues that Canon makes decisions based on solid market research, it would be wrong to assume that market research alone drives design decisions.
Here are a couple of examples. If Canon conducted market research asking potential customers if they would prefer that a 70-200mm f2.8 lens can or cannot take a 1.4 extender, it doesn't take a rocket scientist to figure out most customers would have picked the ability to take an extender. Similarly, if Canon polled customers and asked them if they wanted a 100-500 mm lens to have a maximum aperture of f5.6 or f7.1 at the long end, or that such a lens would take an extender through its full range or only from 300mm onward, it's safe to assume most customers would choose the faster lens and the wider zoom range.
But, market research cannot overcome design limitations and the decisions that limited the features of these lenses certainly came down to design issues, balanced against an informed decision about what the downsides might be for marketing the lenses.
Which brings us to the R3. None of us knows which of the features of the R3 were determined by market research and which were determined by design and budget considerations. A 24mp sensor will certainly move data faster than a 45mp sensor. A 24mp sensor will certainly clear the buffer faster than a 45mp sensor. Could a 45mp sensor move data as fast and clear the buffer as quickly as the 1Dx III? I imagine that may very well be a financial decision -- To hit the price point of the R3, which will be below the 1Dx III, I doubt if Canon wanted to invest in design and manufacturing changes that added significant costs over the 1Dx III.
There is also the great unknown -- the rumored R1. No one on this forum has any idea what the features of the R1 will be (or even if there will be an R1). But, we can all assume that the R1, if it materializes, will be "better" than the R3. We just don't know what "better" means, even though everyone has an opinion on that.
All this is a long winded way of saying it might be prudent to dial down the insults a bit since we all are posting from a position of ignorance.