If this in the context of the BBC Micro, Acorn had already used the 8271 for floppy support with previous “System” and “Atom” models[1], so it’s probably chosen through inertia from a previous design choice.
As for the older systems, does anyone have a date for the WD 1771 (the more common alternative)? The data sheet shown on the Wikipedia page is dated April 1979, and if that’s the release date then it would have been a new, unproven part compared to the intel chip when the System and Atoms were released 1979/80, assuming the floppy drive was an early upgrade (again, I don’t have dates to hand).
Google Books shows the WD1771 available and in use in 1977 with more products using it in 1978.
(I find Google Books very useful for this sort of archaeology. Change the time range to "1977-1980", search for "wd1771", and then sort by date. Of course this isn't thorough, but it gives a good overview for little effort.)
Off topic but I wish Google allowed doing the same for web results, to search their index the exact way it was some number of years ago so that it would only show results that had actually been indexed at that point in time.
Very believable that there was institutional inertia for using the chip that they already understood well instead of a brand new chip just appearing on the market. The new chip might be better but you could lose a month or three of development time integrating it, assuming you don't run across an unexpected bug.
But at the same time it's no surprise that later models switched over to the cheaper and more technically capable chip.
As for the older systems, does anyone have a date for the WD 1771 (the more common alternative)? The data sheet shown on the Wikipedia page is dated April 1979, and if that’s the release date then it would have been a new, unproven part compared to the intel chip when the System and Atoms were released 1979/80, assuming the floppy drive was an early upgrade (again, I don’t have dates to hand).
[1] http://chrisacorns.computinghistory.org.uk/8bit_Upgrades/Aco...