RE: the question: ":Why do forum interactions become contentious". . .

I've just had a very unexpected and very unpleasant PM from a forum participant. 

He'd been suggesting I buy a certain component  and I told him politely that I didn't visualize that particular purchase fitting in with my long-range plans.  

His response was to accuse me of wasting everyone's time and to call me an "effing idiot" (except he spelled "effing" correctly). 

The great majority of interactions I've had here have been very enjoyable and recent input from
more experienced forum members has helped greatly in clarifying my plan for the next upgrade cycle. 

The thread on lesser-know Jazz has been great-- lots of participation and lots of terrific suggestions. 

Nevertheless, I've decided to take a break. 

Best regards,

Stuartk