His point is sound, but it dodges the real issue:
1) Most of the time people aren't doing forms submissions. It's somewhat of an obsolete concept. We use HTML for that. We use PDF when we want to print something.
It's not an obsolete concept - HTML fails if you don't have online access or if you need a wet signature. Sure you can print out the HTML form but it's going to look like crap.
2) You can have Javascript that can do form validations without giving it commands like "open this file, write to it, then execute it" Adobe's Javascript security is stuck in 1998, back in the days of ActiveX controls that could trivially to break out of the sandbox.
Adobe's security specifically doesn't allow you to do those kinds of operations unless you have access to the user's hard drive beforehand for installing trusted functions. Only really useable in a networked office/enterprise.
Why PDF vs HTML forms? You don't have to be connected to the internet. Forms can be saved partially completed and be finished later (with Reader Extensions which allow saving, among other things, with Reader).
Do you need a signature with that form? HTML fails. With PDF you can print the form out, sign it and send it in - with 2d barcode technology that form can be scanned in on the receiving end and all data retrieved electronically.
Why Javascript or any other scripting ability (there's also FormCalc in PDF)? Besides error checking, math and other obvious things - interactivity. I can have the form adapt as it is filled in. Clicked a checkbox that says you're not married and don't have kids? You won't see those kinds of questions later on in the form.
This only scratches the surface - with the full suite of LiveCycle server technology you can do some pretty amazing stuff.
PDF was developed as a document exchange format. It had absolutely nothing to do with prepress, that didn't come about until version 3.
How to Brew Beer in a Coffee Pot:
http://www.allaboutbeer.com/features/235coffee.html
Whom the gods would destroy, they first teach BASIC.