Same thing with consulting, a friend works for a consulting company that closes 1M+ projects. He on side make websites for small businesses. Everyone knows at his company, no issues so far.
It is not the responsibility of a single employee. Even more in a market so ubiquitous as "ecommerce".
The same way, Amazon (and other tech companies) impacts negatively the careers of its employees when it change platforms, frameworks, technologies or do a layoff.
To your second point, sure, employers hold more power. What is wrong with that? If you don't like it, you can always work somewhere else.
Because every software engineer can impact their own revenue the same way.
> To your second point, sure, employers hold more power. What is wrong with that? If you don't like it, you can always work somewhere else.
Don't liking it, I'm supporting my peers in HN that it is not unethical to have a side project and use it as a leverage to not be subject to the humor of your boss. It is also good for the company, as desperate people aren't creative.