Number field validation

entering a nonnumeral value to an integer field
results in an empty field without any validation error,

it jast says: %start was changed to %value; after savig the content .(and value is an empty string)

documents in function number_integer_validate() (number.module line 476) says: // No reason to make this an error, just need to inform user what has changed.

but why? It is a validation error so why we should save an emty field to database? setting a validation error makes user to enter a correct number.

float and desimal fields also have this problem.