Opinion is to each posters experience and knowledge. I am dismayed whenever a poster is attacked for sharing their opinion, particularly when that opinion apperars based in fact and experience. Attack tends to give credence to the opinion of the first person rather than to the second when expressed as defamatory of that opinion.
An early lesson in Debate Class was to keep an open mind, listen, learn, never defame those you do not agree with. You demean yourself, loose validation of your argument when you reduce your opinion into attack of anothers position. The purpose of debate is to inform, speak to those who listen cajole the others into opening their closed minds to other possibilities. Hey, the world was once flat?
A poster in this thread to my belief has been subject to invalid attacks on his opinion that he has validated with experience