Absolutely. For most of the existence of Windows, even when it was notably insecure, the vulnerabilities were all the worse because most users routinely used "Administrator" as their default account. For many years this was in fact the default out of the box, so no wonder that it was such a common thing. This then precipitated the number of software applications that required Administrator permission to install or in some cases even to run, because it was assumed this was "normal" anyway.