As someone who has several books on the go at the same time I have found a Kindle to be very useful and am on my second after wearing out the batteries of the first through use.
While I agree that the prices are high on the UK Amazon site this does include VAT which is not charged on printed books, although this is set to change.
The licence (You do not own etc etc) is similar to most other software which is what an eBook is and while you certainly own a physical book you can't copy it etc and if the physical book is destroyed you don't have any rights to the text anymore either – I can't see this is very different to the eBook situation.
I my case I can therefore live with the Amazon licence. I also use the free online sources and save a bit on Kindle books being cheaper and a fortune in not having to buy more bookcases!