In my life I've also head some bad 'seasons' in which most of my breeding projects resulted in dissapointment or failure. It's tempting to think it comes down to something "in the air", but I concluded such a thing is highly unlikely.
I've noticed that it was often my own fault, for keeping too much livestock at the same time. When I brought my number of species down, I seemed to have more succes per individual species. This allowed me to give them more individual attention, and observe them more, and clean them more regulary (hygiëne is very important).
In some occasions, environment hazards can negatively affect Lepidoptera in your environment, such as the common and widespread spraying of Bacillus thuringiensis, and various pesticides - some pesticides have the by effect of making adults less fertile(!)
For example: Dutch Butterfly Conservation and Wageningen University both rear Pierisbrassicae butterflies, for education and research, respectively. In 2010problems occurred when reproduction failed at both locations. The causeeventually was identified in the use of the pesticide fipronil for coatingthe seeds of the cabbage plants. The delayed effect of the pesticide,becoming apparent only at the adult stage, stresses the seriousness ofsublethal effects of the new generation of systemic pesticides.
However, I find it highly unlikely that such a thing will affect multiple species that you're trying to breed in captivity at the same time, especially if you keep the animals indoors, and especially if they are butterflies and moths - which have wildly different mating rituals. So generally, I think moments like these are just attributed to human stress or error, or maybe our setups.
" I assume females raising and extending their abdomen to approaching males is a 'provocative sign', expressing willingness to mate."
Interestingly, the opposite is true; extending the abdomen into the air is a mate refusal position (the female is not interested) in many butterflies. Maybe the females are not attracted to your males? Are they perhaps related?
Perhaps this gives you some new ideas?
-Bart