after reloading for 54 years I don't care what people call them if they call them bullets or heads I know what they mean and after 54 year I have nothing to prove
The main problem with the use of 'heads' for bullets is, as has been pointed out, the risk of supporting and encouraging ignorance to the extent that it may give rise to dangerous misunderstandings of related terms such as 'headspace': misunderstandings which might have been avoided if folk who actually know better stuck to the correct usage.
I can imagine that experienced sportsmen and reloaders have nothing left to prove. But this isn't about them.