You're entirely right. The person you're responding to doesn't sound like a senior engineer so much as a grouchy old engineer who is burned out. Of course, you can get bad clients but expecting them to know exactly what specs they want every time is unreasonable in most situations, particularly if they don't have the technical knowledge of the systems you work in.
You are either immature as a software engineer and unfamiliar with how software work is done conceptually, or you are jaded and disgruntled from dysfunctional orgs that cannot come up with requirements. That is okay, but you should not try to be instructive to others on this matter.
I love product work and programming. As I wrote in this thread, I did it while freelancing, I do it now at dayjob. I am bored by just programming and want more control over the result. People come to me with "a few words about a desire" and I do come up with specifics and I get credit for it
But I am recognized as a product person, not just programmer. And I know better to not make the mistake you make and pretend that every builder or a structural engineer should be an architect of a building or an urban planner.
People like you is why we have managers come to an expert level say C++ dev with "a few words about a desire" and expect them to decide what thing to build in the first place AND to build it, just to later tell them it was wrong. When there is no product person who determines the reqs random people will make programmer come up with requirements yourself and then later tell you it is not up to "requirements".
This lack of organization and requirement clarity is offensive to expert programmers and probably the reason most projects drag on forever and die.
