> I could find in there was that the author does not like the people using/doing research in geometric algebra
The start of the article makes a specific technical claims:
> Hestenes’ Geometric Product is not a very good operation and we should not be rewriting all of geometry in terms of it
Later he explains why:
> there is no good general interpretation or usage for the geometric product or mixed-grade multivectors
How is the geometric product any less motivated than any other notation? Ultimately the value of a notation is how easy it makes it to work and think. I'm not sure if GA achieves that or not, but what's the harm in trying a new approach?
AFAIK nobody is proposing to replace all of geometry with GA, only 3+1 spacetime.
He's distressingly wrong about this, the geometric product is transform composition
(Apologies to folks who have seen me repeat this a million times; but it's very important folks be aware of it)