Opinions fly off everywhere and yet some people will only accept qualified opinions. Qualified opinions are not necessarily sound opinions. I have heard some very solid non-qualified opinions which need recognition.
Qualifications do give you a platform, but they don’t necessarily make what you say as being sound.
Opinions should always be sourced but very often down right common-sense opinions or opinions from a long life of experiences can often trump the qualified text book variety.
Always keep your options open when it comes to opinions.