You may have a point. I'm going to go reevaluate my entire worldview for a bit.
EDIT: nope, still not buying it. I can only make it work by analogy with bury->burial, archive->archival, and there's not enough there.
EDIT: nope, still not buying it. I can only make it work by analogy with bury->burial, archive->archival, and there's not enough there.
(forming nouns, especially of verbal action.): arousal, arrival, bestowal, betrothal, denial, disposal, proposal, rental, rival, reversal, removal, subdual, submittal, transmittal
https://en.wiktionary.org/wiki/-al#English
That said, substantivization of adjectives is common. Even adjective is itself a word that was originally an adjective, but has been substantivized into a noun. It's a well-known linguistic process:
"Conversions from adjectives to nouns and vice versa are both very common and unnotable in English"
https://en.wikipedia.org/wiki/Conversion_(word_formation)
This process has become especially common in Modern English as inflexional endings have been abandoned and speakers rely almost entirely on word order to deduce parts of speech. Converting a word from one part of speech to another simply involves putting it into the proper place in the sequence. However, substantivization of adjectives is not exclusive to English (in Latin, for example, you can slap practically any adjective into the neuter and use it as a noun, whence we receive such words as animal and dual).
Language in general is very flexible.