kind of a noobish question but why not sort of raise the number of blocks instead of increasing their size?
Because of the 10 minute limit: blocks mut be generated approximately every 10 minutes. If you want more information, you need bigger blocks.
ah sure, but doesnt 'more nodes and/or miners' also implies 'more information'?
Not quite. It is more infomation, but because of the 10 minute limit, it's information that will be sent slowly. Imagine watching an HD video streaming on a 56k connection.