Why is it that threads on open forums generally decline into slanging matches?

Now where are those piegeons?, 'cos here comes a big fat cat.......

Turnover for Tuesday/Wednesday.........$13178
Profit.........$415

Risk......(wait for it....) nil.
Bank $800

All using maths, no form, no handicapping, no risk.

Having said that, I believe that maths is not the only way to go, but it is my weapon of choice.