Yeah, I did mistake Class::DBI for DBI.
You make good points and are being entirely reasonable. Kudos for that!
The synergies that I talk about are not available in all MVC frameworks, well at least not the ones where you have to cobble together an MVC solution from multiple libraries (which is typical in Java).
I'm mostly see switching from Java and PHP, and some from Python. There might be some Perl switching (obviously not from Maypole :-), but I'm not personally aware of any particular instances.
Even though it may not seem like it, I'm not religious about Ruby or Rails. I am, however, very strong on productivity. I think Rails has this nailed at the moment, but that won't last forever.
I'm happy to see viable alternatives. Django looks promising, and I'll keep my eye on Maypole, too.