The web is not in good shape: think about how often we find ourselves confronted with broken sites. One in four websites are currently on Wordpress, where some 70% of installations are vulnerable to attack. Not so long ago, 12 million Drupal sites were compromised by malware.
Over the years we have found that there are huge advantages to testing. However, we have also found that the process brings with it certain problems, some of which are not easily solved. One of these is explaining the value\cost of testing to clients, and deciding whether to confront the issue during the sales phase.