Mostly they're being polite (and showing they understand perfectly well how they could use it, so no need to explain its purpose any further thanks). They're not really misleading themselves...
Ultimately the author's problem is that he was showing Susan a clever project that looked much more attractive than notes she'd usually consult rather than asking her how many times a year she wasn't sure what to prescribe and how difficult it actually was for her to get a sound recommendation from a source she trusted.
Even if he was trying to demo a finished product rather than figuring out if it should exist, asking those questions would still have been more likely to put her in the frame of mind where she asks about or spots the really difficult to ascertain info that has professional liability repercussions rather than just liking the UI and being impressed that this programmer is citing the Hamilton Rating Scale for depression)
Ultimately the author's problem is that he was showing Susan a clever project that looked much more attractive than notes she'd usually consult rather than asking her how many times a year she wasn't sure what to prescribe and how difficult it actually was for her to get a sound recommendation from a source she trusted.
Even if he was trying to demo a finished product rather than figuring out if it should exist, asking those questions would still have been more likely to put her in the frame of mind where she asks about or spots the really difficult to ascertain info that has professional liability repercussions rather than just liking the UI and being impressed that this programmer is citing the Hamilton Rating Scale for depression)