"...เราไปสอนว่าชีวิตคือทุกข์ เกิดแก่เจ็บตาย..." this is from really 'pessimistic' teachers.

If we don't notrealize that เกิดแก่เจ็บตาย is just "ธรรมดา" (dhammatā - a law of life of composite things/beings -- elemental things such as atoms, ธาตุ, particles,... will need more thoughts), we are definitely as you say 'full of avijja' and will need a lot more sikhā to gain paññā and happiness in life.

I support more discussions, free and open forums with the Buddha's teaching as a guide -- so that we can keep in the middle -- not sway into extremes.

Peaceful resolution is far better than bull dozing and rebuilding ;-)