There are several problems with the question:
Issue 1: The question assumes that passivization is actually a process that exists in language. It's carried over from the transformational heyday and feels so normal we might not even question it. But this is the context in which it should be questioned. In the constructional paradigm, this question does not come up because both passive and active as separate (if related) constructions, so you would not look at how one transforms the other. Instead, you would look at how each of these constructions could express similar meaning. And as several people pointed out that is very much possible.
- I was struck by his excessive candor (his excess of candor).
- I was impressed by how far fetched her ideas were.
Issue 2: You're focusing on the passive construction instead of the verb a noun as adjective construction. Something is clearly going on there with how it works.
Issue 3: Before you can deal with 2, you have to leave the realm of generalized syntax and focus on constructional semantics (Note: This is similar to the argument by Sportliche 1990 mentioned by Alex B. but without postulating new entities).
This would be best helped by some more real examples. I went to COCA and searched for .[v] .[p] as .[j]. This generated some more examples that suggested more of a context.
It would appear, the 'as something' only works when there is no force schema implied by the 'agent patient' relationship. For example, you have no problem with the passive equivalent as you can see in 3 and 4.
- They viewed me as excessive.
- I was viewed by them as excessive.
But you can even get the active construction to not work as in 5 or 6.
- *She struck him with a bat as excessive.
- *I impressed my seal into the wax as excessive.
You clearly have to use the metaphorical meanings of 'strike' and 'impress' where the force dynamics is suppressed. Here are some more corpus inspired examples.
- It struck me as a bit odd. / ?I was struck by this as a bit odd. / ? I was struck by this as a bit funny.
- She saw them as human. / They were seen (by her) as human.
- The police identified them as gang members. / They were identified by the police as gang members.
- They identified themselves as heterosexual. / *They were identified (by themselves) as heterosexual.
As you can see in the difference between 10 and 9. The AS construction can accept a more explicit agent-patient schema when dealing with a noun but the passive version somehow makes the schema too explicit with a property unless the verb itself suppresses the schema (as 'view' did in 4.)
There's probably more to the subtleties of the AS construction in different meanings but I hope I showed, that this is ultimately not about the passivization (should something like that even exist).
being
can be done in active tense: "... as being excessive." In passive tense "being" is needed.