WHY DO SOME AUDIOPHILES THINK YOU ARE BRAGGING WHEN YOU ARE SHARING?

Maybe it's the way the sharing is phrased. 

How many threads on this same topic does it take for all of us to be in awe of that particular system and it’s cost?

Many people have decent systems and live happily ever after. Without ever starting a thread about it. Much less multiple threads of same meaning.

I once saw a poster that said something like "The worst thing about being better than everyone else is that they think you are pretentious."

 I think one problem is that people with super high end systems, cable burners, room treatments, special power sources, little brass bells all over the walls as room treatment, etc, etc, etc, will often be a little condescending to those who don't. That sets up a stereotype (ha ha) and then someone innocently posts about how great their new high end system and all its tweaks are....and they get stereotyped unfairly.