BA are just doing what everyone else is doing. Being 'decent' does not get you customers any more.
Unfortunately, across the last 20 years, the public have regularly confirmed that the 'headline' price is what catches them. Also, a very large number of people now book through search engines - these ONLY look at the headline price. Sometimes the pax do not realise there is a tech stop or full transit until after they have booked. Earlier this year, friends of mine did this travelling on BA and then found they had booked the chepaest option without a checked bag. As they were going to a wedding in Italy, they needed full suitcase allowance and had to add in later. I don't know if the total was then more than they would have paid if they had done it all direct.