I'm all for there being a combined MAME and MESS build.
If you want me to give some reasons, I can come up with two.
First reason comes out of one of the responses from etabeta to NLS.
As etabeta writes, "sub-builds" are not possible because,
"if you don't build the whole tree, you could break some dependence".
However, this also means using the now unified source tree to build
the "sub-build" MAME could break some dependence for MESS.
This means building and releasing MAME separate from MESS causes
extra work needed to be done when it comes to releasing MESS.
Releasing both as a unified build would mean developing both together
and catching that breakage when it happens.
Second, it doesn't look good if MAME is not able to provide a unified
build while at the same time you can find it at the blog of an
As to whether or not it should have everything, pinball and poker
machines, I think it should have what MAME and MESS has combined.
What that is, should of course be up to the devs.