Kazakhstan's low-tech approach is just that, low-tech and low-effort. They could have used tons of vectors besides simply saying "install this cert."
A tiny shred of effort would have been to package an "updater" that did the install without explicitly saying that's what it was for. Or better yet: Kazakhstan is committed to a greener more ecologically friendly future! All tax documentation will go paperless! Just use the provided USB Key to access your documents in electronic format!
A small morsel of effort would be to force it on OS vendors through regulation/licensing/threats/money for localized copies. A good deal of effort would hijack CRLs, pinnings, et al while demanding/sneaking the private keys of the CAs.
Public Key Infrastructure is fucking pointless when the infrastructure is precisely what you can't trust.