i place all of the modern coins that i get back into circulation. i don't even bother with sending any of them in to be graded. the same is true for the lincoln wheat cents that i get, even if they are pre-1940 and pre-1930. the only exceptions are if they are 1. brilliant uncirculated and 2. pre-1940 AU or better. i cashed in some coins with coinstar last week and i included some circulated teens and 20's lincoln cents and a 1909 lincoln.
A lot of dealers circulate all their moderns as well... ...bless them. But it's very detrimental to their customers and especially those customers who sell thenm valuable coins for almost nothing because the dealer is ignorant of current pricing.