[Supperman]

Thank you, RickOShay,
I've got your point.
It's a simple solution.

We can't say "chair" instead of "chairman, chairwoman, chairperson", because it is something else. Yet, we may say "fisher".

@Columbine
Thanks.
I agree with your point. Though I can't find "fisherwoman" in my dictionary, Google hits thousands of websites which has "fisherwoman" in it.

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According to your advice, if someone says "fisherperson" instead of "fisher" or "fisherwoman", I can feel his/her strong will that he/she is a feminist.
"I'm a feminist, feminist, feminist!! Women are not inferior to men, and at the same time, vice versa. "Fisherman" is unkind to women. "Fisherwoman" is unkind to men. Fisher" doesn't contain the connotation of me-being-a-feminist. So I dare to say "fisherperson" which has two connotation; one is sexually neutral, and another is "I'm always thinking about feminism!""

When I read some articles which have "Fisherperson's Wharf", I realized that those articles are referring to 1970's exaggerated feminism sarcastically.
And I'm very pleased to know that those attempts to change the name turned out to fail.
I personally think it is ridiculous to change the name.