Here is are some evidences that sitewide links is not bad:
1. cnn.com look at the footer, there is a link to other websites like cnnchile.com
As Cnn is a news website, i guess cnnchile.com receives tons of incoming links in webmaster tools.
2. Lots of websites have sitewide links to facebook and twitter. I didn't impact facebook or twitter pagerank.
3. reuters.com have also sitewide links in the footer. For instance, they have their support team website called zendesk.com or their corporate website which is thomsonreuters.com Both of those URLs appears on every reuters article that are posted everyday. Since reuters is a news agency i think there are lots of new pages everyday.