Nothing to do with the pads.
It's all to do with keeping the callipers nice and clean.
They have moving parts. If you use the bike in all weathers then expect trouble if you don't keep the brakes tip top.
I do many thousand of commuting miles a year in all weathers using BB7 and discobrake pads with no problems what so ever, due to my cleaning regime.
Lejog - GT85 is your friend
I've never needed to apply GT85 to my BB7's. Just a good clean and once a year I take the brakes off the bike, take apart and clean thoroughly. What I also do is smear a small amount of grease on the reverse of the pads before putting them in.
Copper (anti slip) grease?