Why do you need an active FTP mode at all?

Question

FTP

I perfectly understand the difference between the active and passive modes of creating an FTP connection. But I don’t understand at all what the profit of the active is, for what purpose 2 modes were made, of which one always works stably (passive), the second works stably only under certain conditions (active).

Answer 1

The second came later, that's all. Initially, the problems that the passive mode solves simply did not exist, then they appeared and it was introduced. Normal evolution.
Now I looked at the RFC, so the first version of FTP did not work at all through TCP / IP ...

Answer 2

Sometimes only the active one works.