Seems to me that the advice in the OP is intended primarily for someone doing a startup (or planning to). In that circumstance, you're probably not going to stick with such a high risk, even for high potential reward, unless you yourself fit into the group that would use it.

That is to say, you yourself are the client (sort of), meaning there's not so much need to make any effort understand the client, because you already know what you know/how you feel about $THING(/etc.).