StartSSL's denying free cert revocation does not make them untrustworthy from a technical perspective. The onus remains on the site owner to implement their site security properly and pay any fees necessary to do that. So the only issue here is a moral one and whether you believe they have a responsibility to revoke these certificates for free.

I think that given the extenuating circumstances, they probably should revoke the certificates if requested, but I have no right to demand that they do so.