You misunderstood the quote.
The point is that people who know what they are talking about can express their ideas in an intelligible manner. For example, while I cannot explain Einstein’s general relativity in its mathematical detail to a child, even a 6 ear old should be able to understand the very basic idea of what general relativity says about the world: the space of universe we are inside can be bent.
Philosophy and social science is rife with obscurantists who can construct systems of mazes of words that, while grammatically correct, are ultimately meaningless. Read e.g. so called ‘post-modern’ writers and you will see what I mean, in fact there is a parody software called the postmodernism generator which strings together random words but in a syntactically correct manner.
It is impossible to reach the eminence of someone like Einstein through plagiarism. Einstein is known for single-handedly constructing relativity but he made contributions to many, many areas of physics and had noteworthy insights about virtually all the problems of physics of his day. Even if Einstein had ‘stolen’ relativity he would still be in the textbooks of many different branches of physics for many other things he contributed.
Reaching eminence at the level of Einstein in modern science means a life-time of noteworthy work. And it is impossible to reach that level of attainment without being genuine – it’s like saying you can ‘fake’ being a footballer like Messi. You can’t because to become someone like Messi you need to constantly play at his of ability and skill, and it’s the same in science – the superstars become so because of constant insight into their fields throughout their lives.
