Faking ignorance could be bliss

Often times, we tried to give positive feedback or suggestions when needed. When we noticed that something or some processes could be improved, I would often voice out what can be done to make it either more automated or make it simpler while maintaining the same compliance or results. 

You know that your opinions are not welcomed when they were rejected countless times. People often see you as their threat or your laziness that doesn't want to do stuff but only complaints (when you gave constructive suggestions). Just do it, that's the suggestion. Try before you give suggestions. If I am new to the industries or matter, I will try countless methods and seek guidance.  If I have been there and done that, it doesn't necessarily matter to many bosses. This is not about seniority. I valued second opinion and don't complain without giving alternatives.

If that party is simple a deaf ear, fake ignorance could be the best alternative. Do what is needed and move on.  Don't waste time arguing. If it is not valued in the first place, it never will.