Indeed. And especially at lower point buys, this can really matter... a Wizard at 22 Point Buy can still have a 16 Int and a decent Con. But a Monk is pretty screwed. Even at higher point buys, a Monk's going to need to boost a lot more stats than a Wizard. This one also shows up a lot in Gestalt builds... Wizard 20//Sorcerer 20 is often actually weaker than Wizard 20 because while you have more spells per day, your lower Int score (due to resources spent on boosting Charisma) reduces the saves against your spells where it matters.
JaronK