Where are the Spider-Girl trades from before she was cancelled? Where are the various incarnations of Excalibur? New Warriors? et al?
Excalibur v.1 has both several Classic TPBs out that collect the initial Claremont/Davis run (starting with
this one); and an upcoming
Visionaries collection for the later Davis run. The later Genoshan and "New"
Excalibur launches from the 21st century are traded in full, so far as I know (certainly the latter are, though why anyone would want that particular series escapes me; they'd do far better to read Paul Cornell's new
Captain Britain and MI13).
The first volume of
New Warriors Classic comes out in August.
All of that is old series that it takes time and interest to go back and collect. More popular works will take priority; their current publications get automatically traded, which I understood to be what we were talking about from the start.
As for
Spider-Girl, it has a line of digests; given how low sales are, I'm not surprised that they've quibbled over whether it should get an upgrade to the larger format.
Regarding
Thunderbolts, I assume, based on your tastes, you mean the older Busiek/Nicieza stuff from the first volume; that was before the modern trade system started up, so, again (Quesada has actually said several times that he's not really involved in how the collections department works, which surprised me).
For every new reader they bring in with this tripe, I submit they LOSE at least one reader, ususally Old School fans. That's why sales are in the crapper, compared to 15 years ago (even if you allow for the "bubble" that hadn't burst yet).
There's no appearance of that; sales rose steadily through the 00s until the current Great Recession hit. Certainly, the new stuff turned off some people, and others simply dropped out of the hobby, but there's no sales evidence that would support such a conclusion, beyond the anecdotal.