just want to point out that the "entropy of 38 bits" comes from the researchers - the first character has entropy of 2.5 bits but not all 30-length 'passwords' are valid, only a very small number of them, according to the researchers.

38-bit keys/passwords are not secure by any stretch of the imagination, no matter how they are chosen. (i.e. even the best random number generator on Earth doesn't help if you can just try every possibility in minutes.)