Why don't amplifier Companies use high end fuses?


My equipment - Raven Integrated Reflection MK2 tube amp 58wpc. / Lumin A-1 DAC Streamer / Synology NAS / Isotex Aquarius Power Conditioner / Furutech Rhodium Plug / Sonus Faber Amati Homage Tradition speakers.  

I have read thousands of comments on upgraded fuses improving the performance of sound.  I am very open minded but not sold either way.  So, the question I have is....if fuses were so important, than why don't Amplifier companies all install them as OEM equipment?  To me, if they are as good as people say, that would provide companies who use them a competitive advantage?  

Every High End Audio store I go to in Phoenix have told me it does not make a difference and is a waste of money.  For the record, I have fuses purchased at an automotive store for under $10 and I think my sound is awesome.  The Company that built my amp tested the Synergistic Fuses and he emphatically said there was no difference.  

If I were to try a fuse for fun, given my equipment, what would your recommendation be to try?  
willgolf
Sometimes I wish science could explain and measure everything...but probably better that it can't 
PS Audio puts audiophile ceramic fuses in their equipment.  I have a NuWave DAC.  When asking about possibly upgrading the fuse they told me I already have on in there.  They even sent me one for a back up if needed.  Its gold plated and ceramic.  It seems to be made just for them.  No name on the fuse. A while ago PS Audio used to sell their own audiophile fuses  When I asked my amplifier company why they will not include an audiophile fuse, I was told because they want the owner to decide that for himself,  since different fuses will make the amp sound differently.
Fuses resonate when active. It appears that the construction of the fuse will effect this phenomena.  If anyone thinks fuses makes no difference?  I do not know what to tell them.  For I have tried several brands and they all leave their own unique signature on what is heard.
If a resonating fuse effects your amp it's a piece of garbage with a very poorly designed power supply.