It's occurred to me why I don't like it when the GPL is called "viral".

The negative connotations of the term aside, the "infection" spread by GPLed code is quite reversible. Simply remove any code from the program which is available only under the GPL from the codebase, replace it where necessary, and commence developing with your new non-GPLed codebase instead. Infections (viral ones especially) are usually a bit harder to root out.