I think to a large extent this message is accurate. It is similar to Whitman's poem, "The World is Too Much With Us." We are busy, overwhelmed with work and school and family, and we tend to become to familiar with the flowers, the sky, a simple blade of grass. We tend not to see these wonders of nature after a while since our minds are on the bills, the kids, the sports, and getting dinner on the table.
Wilder gives lots of examples of this in the play where the dead are speaking to one another and even with some of the instances of the speech of the living. The subject of daily life becomes to some a ritual and one that is not all that interesting...filled with hum-drum routine. Even Mrs. Soames comments from the grave, "My, wasn't life awful--and wonderful."
Emily's comments to the Stage Manager also reiterate this message. Speaking about her twelfth birthday party, she says, "We don't even have time to look at one another." After one last look at Grover's Corners and being alive, Emily tells the Stage Manager she is ready to go back to the graveyard. She asks, "Doesn't anyone ever realize life while they live it? Every, every minute?"