Well they kinda did. The early rails was rarely well documented. You had to buy books (developed by the rails team) to get everything together. At least I felt this way when I dived into rails pre 1.0.
I'm not sure it's fair to criticise a company that puts it's secret sauce open source under a very liberal license for not spending more resources on writing free docs as their main priority. The growing community very quickly took up on that one and the docs got very good fast.