@jonny@neuralreckoning@elduvelle
Yes, this is approximately (but not 100%) true. The rationale behind it (not advocating for it, just explaining) is that you need to do something that pays your salary. If you do get a 9 months salary, you probably do so because you teach (tuition paying individuals). Typically you only engage in that 9 months a year (and you spend the other 3 doing research).
Medical school faculty don't teach; instead, they draw the bulk of their salary from grants. But not 100%, because they do participate in service. It ranges from ~60-90%. If you ask the money guys at a university, they'll tell you that they barely break even with grants (including overhead); if the salary isn't going to come from there, from where then? Of course for clinicians this is a different story (they provide a bankable service).
Someone with a 9 month salary can draw those extra 3 months from research grants as well (if that's what they are doing those 3 months).
There are other things that you can engage in that also cover those extra 3 months (like admin such as serving as department chair, etc).