I suspect it's because the queens have a reputation for dying BEFORE getting to having 5 workers.
The consensus before this year was like a 3 in 4 loss rate - "buy at least 4-5 queens" has been the advice, unless buying an established colony.
This year people have done very well with the queens, especially those who collected lots of queens and have kept them in the months since then. My own rate has been pathetically bad, probably because I didn't have appropriate heat until pretty late, and also probably from shipping stress (a couple of them died within days of arriving).
Once they have a good number of workers, they do not have a reputation for dying, except that they are notoriously difficult to move. You can find videos of Nurbs showing how he moves the repletes.
Past & Present
Veromessor pergandei, andrei, stoddardi; Novomessor cockerelli
Camponotus fragilis, Camponotus sansabeanus (inactive), vicinus, laevigatus/quercicola, CA02
Pogonomyrmex subnitidus, P. californicus (inactive)
Liometopum occidentale (inactive); Prenolepis imparis; Myrmecocystus mexicanus (inactive); Tetramorium sp. (inactive); Lasius sp.
Termites: Zootermopsis angusticollis, and a box of drywood termites that can't be seen
Isopods: (most no longer keeping) A. gestroi, granulatum, kluugi, maculatum, vulgare; C. murina; P. hoffmannseggi, P. haasi, P. ornatus; V. parvus, P. pruinosus, T. tomentosa
Spoods: (no longer keeping) Phidippus sp., other