Can you feel my pain? I've been asked this question so many times by people that know I do content development for a living that I’ve lost count!
It's not that they're trying to get away with not paying a fee (well, maybe not!) but I do believe it is mostly because they really do think that if you like to write, and can do it reasonably well, then it makes sense that whatever they want you to write should take a minute or two.
The fact is that you can't write much of anything in a minute or two and even if the minute stretches into ten or twenty the results of that rushed writing job with little background or prep time is usually inferior.
Why would anyone want that type of work?
Of course the truth is that no one wants substandard work; they want excellent work, work that deserves time and effort combined with skill so it can generate the best possible outcome.
The kind of work that takes more than a few minutes.
The kind of work that professional writers do each day for their clients.