I think we can compete -eventually.
Pier/seaside
etc are developed with a minimalist philosophy.
Plone/Zope
etc have an everything and the kitchen sink philosophy.
If you spend time integrating all of the minimalist bits we already have
then we may start to have a platform which can compete.
e.g 1 x Magma Server to n x Pier clients should work "out of the box".
Its just a matter of trying it and doing the configuration.
Personally I am a kitchen sink kind of person since it takes me a lot of
effort to see the path from A to B without concrete examples.
At present building pier/seaside apps are like building a den with lego
rather than cardboard. You can assemble what you want out of lots of
little pieces, and it will be quite robust. If you want a custom piece
you take one you already have and adapt it a bit and carry on building.
With plone/zope, you take your cardboard boxes to build your den, the
boxes are bigger so you could build your whole den very easily, but
adapting boxes is much harder because they are a bit more flimsily
assembled and the underlying frameworks are not so concise. My limited
experience of zope a few years back when I did attempt to use it for
serious things (my ex-company corporate site uses it even today) under
the hood is that it is awful code/design. Easy things are easy and
slightly more difficult things are impossible.
In smalltalk/seaside everything is moderately difficult, but everything
is doable in a moderately difficult kind of way..
When you add pier, it becomes, some things are easy you just configure
and arrange the components, and the rest is moderately difficult, but
still everything is doable in a moderately difficult kind of way once
you understand it.
If you want to build a mansion out of card board boxes then, you will
probably get going quite fast.
If you want to build a mansion out of lego its going to take some time.
best regards
Keith