Creating an unplayable character is not as easy as you make out. Just because you don't have the most powerful spell for your level doesn't make that character unplayable.
No, but when you have a low-level character that doesn't have /the only viable offensive spell of his chosen element/, it can.
Hence why i separate "low-level" with mid/end-levels. It matters much less once your character has some versitality if you have to wait a bit before the next big thing (and it makes finding it great), but when you are at low-level it can be crippling.
It's bit like how in BG2 the only way to get pierce-magic was through random loot. You almost always got it- but when you didn't, it was 'oops, can't do half the content right now'.
