Let’s pick apart the semantics of “tax rise.” First, because it is an unaccusative verb, the subject — tax — undergoes the action of the verb. Second, because the verb is intransitive, while the subject undergoes the action, it has no direct obect. So what is actually going on — I, the citizen, am paying more taxes — is completely erased from the semantics.
Now, let’s contrast that with American English “tax raise,” or if you prefer the verbal form, “to raise taxes.” “Raise” is a transitive verb. Even though the phrase usually doesn’t appear with an overt direct object, “raise” is not an ergative verb, that is, the subject performs the action whether used transitively or intransitively, and the direct object is always implied, if not stated. “To raise taxes,” or “tax raise” semantically has an agent who performs the action — the politician — and a direct object who undergoes it — the citizen who will pay more taxes. So unlike “tax rise,” what is actually going on is never erased linguistically.