Please read the full context of the conversation. This is not a discussion about whether a specific poor person might have enough dollars in their pocket to buy disability insurance. This is a discussion about whether or not poor people have the cognitive ability to purchase disability insurance. The OP suggested that by the very nature of being poor a person should not be expected to be able to attain the "expertise" required to purchase disability insurance.

My contention is that this is a disgustingly classist view against poor people. Poor people, by and large, seem perfectly capable of purchasing car insurance, and disability insurance is generally less complicated.