"He's basically exploiting a narrow arbitrage opportunity and is probably either unethical or lazy"

This sentence made me uneasy. I am not good identifying sarcasm so it might be that but... How one would jump into that conclusion without knowing any detail?

On the other hand, lazy is different from being not ambitious. I had several friends like that (not making 5 figures per month though)and I find that is a very legitimate way of live.