Yeah but you can do that by means of "salary and work hour discrimination," see what I'm saying? Those are things you can state outright, legally. Just make it clear that those are parameters of the job, and if they accept the job, they accept the job. I dunno maybe I've gone completely batshit crazy up in here.
No, you're right, they are just doing it the quick/lazy way. Older workers are also less liable to drink all the other corporate koolaid that might be harder to test for.