Well, 3-Tier is definitelly not a myth, I saw it a few times. :)
Before using new framework, like Linq2Sql, we have to get a thorough understanding of how it works. More than that, we have to change the way we think about some problems and solutions. I expressed concerns a few days ago when someone asked how to use Linq2Sql to create complete Data Access Layer, but I was probably misunderstood by many - I don't think Linq sucks. It is fantastic. But, before using it in full speed, we need to start thinking that way. The problem is not in Linq, it is just we need some time to adopt a new paradigm. Our brain needs some time to adopt new way of thinking. In your and Rick's case, I think you've tried to solve the problem as you used to do before and hit the wall. This is not the reason to "abandon Linq to SQL".
Cheers,
M