As Dentrasi has explained - this is to make it more difficult for the attacker to carry out a brute-force attack on the password store. In almost all circumstances, you don't to change this behavior.
If you have a good reason to (which I can't think of), you can modify it via
/etc/login.defs - See the login.defs(5) man page.
Delay in seconds before being allowed another attempt after a login failure.
Hmmm... At the end of the manpage...
Much of the functionality that used to be provided by the shadow password suite
is now handled by PAM. Thus, /etc/login.defs is no longer used by passwd(1), or
less used by login(1), and su(1). Please refer to the corresponding PAM
configuration files instead.
The appropriate PAM entry instead...
# Enforce a minimal delay in case of failure (in microseconds).
# (Replaces the `FAIL_DELAY' setting from login.defs)
# Note that other modules may require another minimal delay. (for example,
# to disable any delay, you should add the nodelay option to pam_unix)
auth optional pam_faildelay.so delay=3000000