Regarding the "nothing to lose" part: wouldn't they be wasting resources mining only BIP110 compliant blocks and ignoring invalid ones, when the majority of miners will mine the BIP110-invalid blocks,...
As I said, it’s a classic prisoner’s dilemma. If say 10% of the global hash pivots to BIP-110 tomorrow, there’s a 99% chance the rest will pivot immediately after. Currently there’s no penalty for doing this which is why only the ideological miners signal at this point. This will change in early August and we have a proven case study from SegWit.