My home airport is GVA and if flying XXX-LHR-GVA I was more than happy to take the tightest connection available as there are plenty of flights LHR-GVA (almost every hour) so if I missed a connection, I could be pretty sure of getting another flight fairly quickly.
Doing the trip the other way, GVA-LHR-XXX where LHR-XXX was only once or twice a day, I would tend to build in a longer connection time at LHR, but not always. I remember once doing a GVA-LHR-IAD with the 60 minute MCT at T5, catching the IAD, but pretty much having the aircraft doors closed behind me and I know T5 fairly well, so don't get lost. There's not much reserve with 60 minutes and it suffices for your incoming flight not to have the gate ready, security to be slow or something similar for you to be running.