I agree, you should be, and are free to air your views, as long as they are reasonable and supported by evidence.
In relation to people jumping down your throat, perhaps you may wish to re-read your opening statement that started this stream. It would seem that you are asking other readers not to do what you have done.
Readers are entitled to be informed of the basis contributors are writing on. Are they writing on behalf of a business or as a private individual, or as a representative of an organisation? Do they have a vested interest? Are they consumers or users of a product/service? Are they relating second hand? Are they trying to promote their own products/service, or perhaps denigrate the competition? etc.
As with any product, or service, or industry, when a contributor expresses strong views as you have, the author's background becomes relevant. The readers should know if you are/were a practitioner or in the industry so we understand where you are coming from.