When I refer to the leisure long haul routes not being "proper" routes, its more due to the fact that they are often served only say once or twice a week or through package holidays. Of course airlines make profit on these leisure routes otherwise as you say they wouldn't operate them.
Maybe "proper" isn't the right way of describing them. Whilst I accept there is demand for them, the fact the traffic is mostly people from the UK travelling abroad for holidays and not people travelling in both directions makes them seem less important.
With regards to Gatwick yes they may well say its more like 50, however recent evidence has shown that less than 10 of these are served on a daily basis, most if not all of which are also served from Heathrow.