Brilliant or sneaky … or both ?
Although I disagree with most of RickC4’s argumentation, I think this has to be considered as an abuse of the repository.
I put myself in the shoes of most users:
1/ Search for a google map plugin
2/ Find this plugin
3/ Because of the number of downloads, I trust and install the plugin
4/ There is an advice from the author (or ex author) that I should try your plugin … why not.
5/ The plugin I install comes directly from your site (not from the repository) and is a premium plugin …
I think your explanation about the spirit of WordPress and keeping the code for hypothetical developers to fork is a bit lame; we both know that the value of a plugin in the repository is essentially its popularity (most people don’t look at the code inside).
I observed that the number of downloads of abandoned plugins does not go down until the message ‘This plugin hasn’t been updated in over 2 years.’ appears.
So you got yourself 2 years advertisement for your plugin … which I find brilliant.
However, it’s also depriving a motivated developer to adopt a successful plugin to make it live properly.
All the best.