Performing or doing something is not always in correlation with describing the actions done, in such way that someone else can improve the same skill.
For example there are some athletes that excelled at their sport, but were not the best coaches for others. Or some who didn’t even been professionals, but were the best coaches.
This is the case also in testing, when good testers are not able to present the parts, approach etc to other testers, so they can become as good at it. It happens because we don’t consciously realize the exact way we perform some actions.
Another perspective related to this can be seen in this video:
which, I guess after the number of views, is funny for a lot of people. But most of the people would not be able to describe what makes it funny. Some of the images there can describe actually small accidents. But there are other videos with small accidents, that are not perceived as funny. So what makes it funny? Its a hard question to answer.
The same can be applied to testing when asking “What makes good testing?” Is not a question with an easy answer. In fact some people have decades in the field and cannot give an easy answer to it.
I think that there are testers who test better than they are able to explain it. I think there are testers that explain better than they are able to test.
This doesn’t mean necessarily that testers who don’t seem to bring value by testing can explain better. And vice-versa.
I don’t see nor a direct proportionally link between the two, testing and explaining, nor an indirect proportional link. I think there is a connection, because is the same area , but in a different way. And each of the skills must be improved.
A tester will not just learn to describe better and teach others just by resuming at testing, but by going and studying other fields.
Also someone who knows to describe things very good will not be of a much help in testing, if he/she is not really doing testing.
People tend to find a quick answer and implement ways of doing testing in organizations that are not very feasible. Just copy some approach and implement. And if it doesn’t work blame others. This is an effect of inability to analyze what makes it good testing.
In my opinion, to become a real professional in the field, one needs to improve both skills mentioned above.