These are the transaction costs, the costs to process the transaction. The user pays the transaction fee which is currently (usually) lower because miners still get the block reward. But at some point in the future only the transaction fees will have to pay for the transaction costs.
You are missing the point. Right now you are getting 25 BTC for mining a block, but that block reward will drop to zero while the costs for processing a transaction will remain more or less the same. Therefore transaction fees will have to go up until they cover the transaction costs without subsidizing them with the block reward. The other alternative, lowering transaction costs, is not a real option because it would make the Bitcoin network vulnerable.
There was only a single drop from 50 BTC to 25 BTC so there is no basis for your claim. And it can not work the way you describe. With 100k transactions per day and $0.10 fees per transactions miners can collect 3.65 million Dollars per year. So everyone with a handful million dollars to spare can easily completely destroy the Bitcoin network. Even better, there are already people with a lot of mining hardware out there, they would only have to pay electricity for a few weeks.
Have a look at the charts showing the fees per day [1] and the network deficit [2]. On the one hand fees went up, but before the block reward dropped, on the other hand the network operated at a deficit for quite some time. One has of course to take these graphs with a grain of salt because it is quite hard to estimated the real costs of running the Bitcoin network.
But I really don't understand what you are arguing for. Once the block reward becomes mostly irrelevant you have essentially two choices - relatively expensive transactions or a weak network, i.e. low hash rate. Don't you agree with that?
