It does not have to be perfect to be better. It's not great that 13% of revoked certificates would still be there (and get trusted by CRL-ignoring clients) but significantly smaller CRL files may get us closer to more widespread CRL checking. The shorter lifetime also reduces the window of time that a revoked certificate can be exploited by that same 87%. While I'd wager most certificates that get revoked are revoked for minor administrative mistakes and so are unlikely to be used in attacks, some revocations are still exploitable, and it's nearly impossible to measure the actual occurrence of such things at Internet scale without concerted effort.

This reminds me a bit of trying to get TLS 1.2 support in browsers before the revelation that the older versions (especially SSL3) were in fact being exploited all the time directly and via downgrading. Since practically nobody complained (out of ignorance) and, at the time, browsers didn't collect metrics and phone home with them (it was a simpler time), there was no evidence of a problem. Until there was massive evidence of a problem because some people bothered to look into and report it. Journalism-driven development shouldn't be the primary way to handle computer security.