I think your point is fully valid. I would balance it with the notion that they (people undertaking huge personal risk) would be better protected - if there was less natural pressure to acquire/release info that gets over-classified to protect political interests.¹

Stated otherwise, if US Gov could be relied on to honor it's ethical obligations to taxpayers and release the entirety of info that it ought, I argue that fewer unqualified people would feel responsibility to take that upon themselves.

¹ https://en.wikipedia.org/wiki/Iraq_War_documents_leak#Civili...