DTML just doesn't scale to non-techies or content people who are talented at HTML, but not 'programming.'
Being exactly what you are referring to, ie: someone who knows html, but not programming, I have to disagree. I tried Zope initially BECAUSE of it's tag based scripting language. I found it very easy to learn, and granted, I have encountered some syntax issues that were a problem for a while, but searching on zope.org and asking for direction from list members, everything has worked out just fine. I constructed 26 virtual sites with Zope and DTML. I have also looked at ZPT and found it rather confusing. I guess maybe it's just the way I'm wired or how I process information, in any case, since we're not all the same, I feel that continuing to offer both solutions would be the most appropriate course.
You're right: if you have good control over all the people working on your site (i.e. by yourself, with other of the Zope-savvy) either templating language can work fine. DTML, being straightforward, might even be easier (depending on if you've been trained to think XMLishly or not.) Note of course that Page Templates *look* a lot more obscure than they actually are. But throw in a couple designers with WYSIWYG editors and all hell's out for noon with DTML, so far as round-tripping your design is concerned. If that'll never happen, don't worry about it; if it might, or will, think very hard. And test the likely tools. There are people who think best in both DTML and ZPT modes, and I don't think it's a bad thing to have both lying around, so long as it is clear that "best practice" involves Page Templates (which I think it does), and the reasons for that are explained. --jcc