I argue the barrier to FPGA adoption is the actual use-case, not the tools. People who need them can use the tools just fine. FPGA designers are not idiots. They do not walk around scratching their heads wondering, "how come nobody is using our products? If only they were easier to use!" There is a new open-source attempt at replacing imcumbent tools bi-annually begun and dropped.

The use cases for FPGAs are a much harder impediment to adoption. Many people get "FPGA boners" when they even hear the word, fancying themselves "chip designers," but practical use cases are much rarer. As evidence, notice they predominate in the military world, where budget is less of an issue than the commercial world.

The technical issue with FPGAs is that they are still one level abstracted from any CPU. They are only valuable in problems where some algorithm or task can be done with specific logic more quickly than the CPU, given 1. the performance hit of reduced real estate and 2. reduced clock speed relative to a CPU and 3. more money than a CPU.

Further diminishing their value is that any function important enough to require an FPGA can more economically get absorbed into the nearest silicon. For example, consider the serial/deserial coding of audio/video codecs. That used to be done in FGPAs, but got moved into a standard bus (SPI) and moved into codecs and CPUs.

Because of this rarity, experienced engineers know that when an FPGA is introduced to the problem in practical reality, it's a temporary solution (most often to make time-to-market). This confers a degree of honor which is why people get so emotionally-aroused about FPGAs.

You can bet though, that if whatever search function Microsoft is running on those FPGAs proves to be useful, it will be soon absorbed into a more economical form, such as an ASIC, or, more likely, additional instructions to the CPU.

Really, installs on 1,600 servers such as this article reports, is not that impressive and certainly only a prototypical rollout.