It isn't a slippery slope at all. The less/fewer rule as most people understand it comes from the opinion of one Robert Baker in 1770, who said he thought it sounded better to use fewer with count nouns. His opinion has been codified into a rule that contradicts both historical and present-day usage.
And to what end? Is anything gained by insisting that it should be "10 items or fewer" rather than "10 items or less"? It doesn't actually make a difference grammatically or semantically. It's entirely a social issue: if you break the "rule", certain people will make negative judgements about you. My thinking that this is stupid and somewhat depressing has nothing to do with abandoning grammar rules as you're implying.
[size=8]Also, I know I've said this before, but I really don't like being called JB, especially since Jon Boy isn't even my username anymore.[/size]