Why do they send spam in wierd fonts?

It seems like half the spam and phishing mail I get is in Comic Sans or similar. Why do spammers do this? Is it just to lull you into a false sense of security? Because I’m pretty sure that, no, the Commonwealth Bank is not going to use a “fun” font in their oh-so-serious mail about how I need to send my account ID and password now or I’ll be deleted from their system. What gives?