@Back at Equivalency Dalek
I will rebut your points one by one!
1)(a) Statement: Yes, I am willing to give TfL the interest on my prepay money.
Explanation: There are two reasons for this. Making the assumption that I keep £50 prepay on my card at all times, at 5% interest (ie the interest gained from having the money in a good bank account) the opportunity cost of the lost interest is £2.50 for the year.
The first reason I am not worried is that this is actually a completely insignificant amount of money. I lose more than this a year through change falling out of my pocket.
Secondly, we make the further assumption that Oyster saves me, an infrequent traveller, an average of 30 seconds on any day I use the TfL network. I think on average it takes longer than 30 seconds to queue and buy a ticket but I'll be generous. If we value my time at the average perceived value of travel time of £22.11 per hour then to save £2.50, you only need to save 7 minutes over the year and the loss of interest is offset by the value of the time saved. So in other words use Oyster for 14 days and you have offset the cost of the lost interest with the reduction in the travel time.
(see http://www.webtag.org.uk/webdocuments/3_Expert/5_Economy_Objective/3.5.6.htm for details on the value of travel time)
1)(b) Actually I think Oyster saves me money because I don't have to plan ahead, I use the system as and when needed and I never pay more than the total cost of a travel card. Before either I bought a travel card and then felt stupid when I ended up using it for only one journey because my plans changed, or I bought a single and if my plans changed I ended up paying more in total than the cost of the travel card I didn't think I would need. With Oyster this is not a problem. Plus tapping in and out isn't exactly rocket science, with a modicum of intelligence it is perfectly possible to always tap in and out.
2) I think you own argument fails here, Oyster may not be cheaper now than paper tickets were 5 years ago but it is still cheaper than other payment methods today!
3) It may or may not be the case that Oyster is slightly slower than the old paper tickets, I haven't found it to be the case. As to human checking, it is fallible and relatively expensive so is not actually a viable option.
4) Erm - who cares about the class of passenger - I'm not there to strike up a conversation with them. Ok, so the system treats everyone like a fare evader instead of trusting people to be honest. Well I'm sorry to say this but the majority of the population are not honest, if they can get away without paying for something they will. However, by making paying easier I think you'll find that the number of people freeloading will actually have gone down.
5) So given you aren't using Oyster you'll actually have been paying more. Heck I don't mind if you want to pay more for the same service, all it does is subsidise my use of the system!!!