Sure they are -- all cosst of doing business is built into every good and service sold. And of course health coverage is treated as a tax deductible expense so the net cost to employers won't affect the bottom line much.
In any case, Denny's and the rest of corporate America had a choice: to engage in substantive discussion about alternatives. Escalating health costs have been a drag on the economy for a long time and companies were quietly (some not so quietly) shrinking their health coverage for over a decade befoe Obama was elected.
I remember being quite hopeful when I read this article in 2007
New Urgency in Debating Health Care; and dismayed by the non-solution we ended up with. Corporations had their chance to get engaged in the solution and declined to do so.