Computer Science history has taught us that this decision was almost always wrong.
Every time a company has spent resources doing this, a competitor innovated on the software and made the custom hardware irrelevant.
Every time a company has spent resources doing this, a competitor innovated on the software and made the custom hardware irrelevant.
This often happened, though not always.
An important counterexample are 3D graphics cards, which basically put the OpenGL/DirectX fixed-function pipeline into silicon. It took a long time and many iterations to make the pipeline more programmable until the 3D graphics cards turned into modern GPUs.
Even today, GPUs live on as separate hardware in a computer instead of having become integrated into, say, the CPU. Intel's attempt to do something like this with the Larrabee project [1] was discontinued.
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[1] https://en.wikipedia.org/w/index.php?title=Larrabee_(microar...
Only when they became more general with shaders, and then added support for GPGPU, did it truly take off.
I think this generality is the lesson here, not the fact that GPUs are not CPUs.