I agree that signatures are of no value unless validation is done... but please do note that current measurements are showing about 13% of all DNS queries globally are in fact being validated:

http://stats.labs.apnic.net/dnssec/XA?c=XA&x=1&g=1&r=1&w=7&g...

If you scroll down that page you'll see higher statistics, such as 70% of all queries being DNSSEC-validated in Sweden, because almost all the ISPs there are now validating.

In the USA, about 23% of all DNS queries are being DNSSEC-validated:

http://stats.labs.apnic.net/dnssec/US?o=cXAw7x1g0r1

So the argument that "no one is checking" is no longer true.