One of Bruce Lee's ideas was that in the study of any fighting art, you should keep the techniques that are useful and work for you and get rid of the ones that don't. He believed that you should question what you learn and not study by rote.
This concept is sound. There is no point endlessly practicing techniques that do not work for you.
As with many topics, there is a caveat. In order to throw out what is not useful, first you need to learn and fully understand what it is you are discarding. You need to fully explore, understand and nearly master a technique before relegating it to the trash.
When I first learned the technique Sankyo, I felt it was unrealistic and believed I would never really use it. I was tempted to give it no more thought or practice and clear it from my mind. Now, Sankyo is one of my favorite techniques. It's one of my 'go to' defenses from strikes, chokes, bear hugs etc. I have learned how to enter into it from a variety of angles and from a variety of attacks. I can apply it causing extreme pain to my opponent while keeping myself out of harms way.
I first learned it from a handshake. The likelihood of applying it from a handshake is low, but it's a good way to learn the mechanics of the technique.
It is important to be critical of what we learn. We cannot be slaves to curriculum if techniques don't work for us. We need to adapt to our body styles and our abilities. If we want to study a martial art for it's combat applications, we cannot fill our heads with unrealistic techniques. However, our minds must remain open. We cannot judge prematurely.
It's the paradox of the martial arts. First you must practice and master a technique before you know if you can throw it away. You must learn it before you un-learn it.