Time and willingness. The people you train to use a typewriter aren't just learning to type but how to provide limited service and maintenance to the machine, which, besides being another responsibility to take on, didn't fit with some people's idea of what a librarian should be doing.
Perhaps you know of a machine like this in your own life, but some typewriters spent as much time broken (ie- no one present knew how to fix, even if it was a simple jam) as they did being usable. And since you could only train one person per machine at a time, either you'd have to send people off for classes (not guaranteed to be on the same model) or limit access to them based on who was willing to become the local typist.
Penmanship is fairly social and a skill many would have already had and prided themselves on. 'Make your letters this way' is a simpler request then than 'learn how use without breaking this expensive and delicate contraption that's more trouble than it's worth'.
Perhaps you know of a machine like this in your own life, but some typewriters spent as much time broken (ie- no one present knew how to fix, even if it was a simple jam) as they did being usable. And since you could only train one person per machine at a time, either you'd have to send people off for classes (not guaranteed to be on the same model) or limit access to them based on who was willing to become the local typist.
Penmanship is fairly social and a skill many would have already had and prided themselves on. 'Make your letters this way' is a simpler request then than 'learn how use without breaking this expensive and delicate contraption that's more trouble than it's worth'.