Yes, embedded systems do need multi-arch!
As an Emdebian newcomer (but long-time embedded Linux afficionado) who
is looking at Emdebian to form the basis of a commercial embedded thin
client O/S for my employer, ThinLinx Inc (thinlinx.com), I was annoyed
to discover that Emdebian Grip (stable, at least - I see from your FAQ
that jessie-grip may be a different story, but that doesn't help me
right now) lacks Multi-Arch headers in its package metadata, thereby
rendering multi-arch effectively unusable even though the package
contents themselves are multi-arch-ready.
The Emdebian FAQ states that "it [was] not expected that many devices
running Emdebian Grip would need to use Multi-Arch", a decision which I
assume was based on reasoning along the lines of "multi-arch is only for
development, so you don't need it on a production system, right?". If
that was your thinking, I am here to assure you that, from a commercial
embedded Linux standpoint, you were wrong.
We do need multi-arch at runtime. We need it because not all code that
we use is open source, or even available to us in source form. Some
industry partners and/or upstream software suppliers are slow to adopt
newer ABIs. Case in point is Citrix Receiver, formerly Citrix ICA
Client. It's currently only available for ARMEL, and we would really
prefer to use ARMHF. It's not so very long since ICA Client was only
available for Standard ABI, and they didn't have an EABI build! Another
example from the x86 world, that many of you may recall, was the Adobe
Flash Player browser plugin - Adobe failed to produce a 64-bit port of
their 32-bit plugin for many years after fully 64-bit Linux systems
I am persisting with Emdebian Grip, because I think that it offers
enormous flexibility at a relatively affordable resource cost, but for
now I'm going to have to maintain parallel ARMEL and ARMHF builds
(either that, or extract ARMEL packages outside of package management on
my ARMHF build, which I am loath to do).
But please, next time you make a decision like this, consult the broader
community first, at least if you entertain hope of attracting serious
interest from industry!
P.S. For others hoping for an ARMHF Citrix Receiver, we have nagged them
about this, and they have assured us that they are working on it!