It's really not clear to me that there's a trade-off between bird impact prevention and drone prevention (or anything else you mention) for two reasons.

First, effort allocation isn't really a compelling explanation -- most of the world just doesn't work in those types of zero-sum terms. Drones are sexy; just because government or industry is willing to fund research and development on safe drone-airplane regulations now doesn't mean it's willing to allocate those same resources to something else.

Second, even when resource allocation is strictly zero-sum, the sorts of calculations you suggest are mostly a matter of qualitative speculation about the future. Which means you're mostly just going through a number crunching process that "confirms" your prior beliefs.

> that common sense "don't fly near airport runways" is sufficient

I think the major challenge that incidents like this one demonstrate is that it might no longer be sufficient to assume pilots have common sense.