I don't mind sending my engineers off to work on certs. It seems like a plausible way to get someone interested in learning some aspects of a tech that they might not otherwise run into -- since a cert covers more things than one would actually use. However I don't consider it in hiring. It's not that I don't value the knowledge that comes from prepping, it's that I believe the long term success of an engineer has little to do with what they are currently working with.