You're right, these companies are out to make a profit. Think of it as insurance for the mechanical wellbeing of your LR3. If you never need it, great, but if you do, you'll be glad you had it.
As an aside, I was at my dealer last week and was getting my keys from the service tech who just happened to be closing an ESP warranty ticket. The final warranty cost was $4,700 and covered front bushing, lower control arms and a compressor. The service tech then made a joke that had this guy's LR3 still been under factory warranty the only things covered would have been the compressor and bushing (because it was leaking).
I'm "lucky" that my LR dealer is also a Mercury dealer (don't ask my why they are combined like that) because I purchased the ESP from them so it makes claims and authorization so much easier- I hope since I've not had to use it yet...