Film prints don’t have a very high resolution. A 35mm fine grain negative might have a resolution of 3-3.5K, but prints have a resolution lower than 2K. 16mm has just 1/4 of that resolution, so less than 1K, and then add to that the duplication process is an unknown too. Who struck the print and why? Was it duplicated and then reduced from a 35mm print for example. A print duplicated from another print instead of struck from an interneg has an even lower resolution, poorer dynamic range, etc. Also, 16mm prints often look quite different to their 35mm counterparts, so you can’t know that your print is representative of the colour timing, brightness and contrast of the theatrical experience. And after all that, unless you’re paying for some substandard conversion done with a camcorder and a dvd-recorder, scanning costs the same as scanning a 35mm print anyway.