Pretty darn dumb, IMHO. *
*DH (who turned 44 last month) and I (37 last January) have almost $200,000 in retirement accounts. *We're young enough that we got the "don't count on Social Security" message drummed into us in plenty of time to plan around it. *Of course, if we actually do get any Social Security money, that's gravy.
Do you agree that we need 100% of income?
Basing your retirement plans on your income alone is, IMHO, silly. *See the 33% threads elsewhere in the forum for specifics.
How much to save for retirement depends on how much you anticipate your expenses in retirement to be--but that's not an easy, quotable answer, so people make up these "rules" for whatever reason. *(The cynic in me says the financial pros make up scary numbers to coax/coerce people into investing with them. *The kinder, gentler me says they're just looking for a sound bite.)
As for inheritance--I'm in an unusual situation: an only child, with a still-living mother who sees it as her mission to leave me as much as she possibly can. To that end, she bought long-term-care insurance at least ten years ago so that her assets wouldn't be eaten up by her care. (Her mother was in a nursing home for more than 30 years, so she had reason to plan ahead.)
That said, most people don't plan nearly as well as my mom (Go, MOM!), and so counting on an inheritance is chancy at best.