At any given time, the lexicon is evolving and some idioms are expanding or on the verge of extinction. Still, there are uses of words and phrases that can reas

At any given time, the lexicon is evolving and some idioms are expanding or on the verge of extinction. Still, there are uses of words and phrases that can reasonably be described as simply wrong at a given time, based on a failure to understand the idiom whose invocation is being attempted. Errors that are sufficiently popular and persistent will eventually just reshape the language, but for a time even an error that is pretty popular or fairly long-lived is still recognizable as an error. By my intuition, I'd say the uses of 'this week' and friends I described as improper qualify handily, not being all that widespread yet. A couple more marginal examples that stand out to me because erroneous uses are much more common: 'let alone' (which is binary and often used with subject and object reversed), the distinction between envy and jealousy. You can take up a radical descriptivist position, e.g., that anything spoken by adult native speakers of normal faculties is never erroneous, or re-scope my assertions by saying that I'm gatekeeping speakers who see such usage as correct from my perceived language community or tradition, whatever, but imo the first is trivial and the second boring. Sometimes specialists misappropriate methodological constraints from their discipline as general ontological or social principles, often discounting an inherent normativity in the way people actually relate to the things those specialists study. I think that's essentially at the heart of the most inflated and controversial uses of concepts like cultural relativism and linguistic descriptivism, and probably applies to nonspecific objections like the one you make above (as opposed to pointing at some specific dialectal variation in the use of such phrases or something like that).