恥ずべき is listed as an adjective in EDICT, as a 'compound word' (連語) in kotobank (here), and as a "noun or verb acting pre-nominally" on the Midori app. My question relates to a sample sentence I saw on EDICT (link).
君は、自分の愚かさを恥ずべきだ。You should be ashamed of your folly.
All the other examples I found are 恥ずべき+Noun
(恥ずべき秘密, 恥ずべき行為, 恥ずべきこと, etc), making them noun phrases. But in the above example 恥ずべき is followed by the copula だ. Also, the inclusion of the particle を would seem to make it a verbal use of 恥ずべき since there is no other verb present.
So is that example sentence correct? If so, how is 恥ずべき functioning grammatically with を and the copula だ?