Most tourists either enter or live somewhere in Melbourne close to the CBD. It is therefore mind boggling that someone could think it hard to get a card. Sure, someone who arrives from interstate by road and has accommodation in a remote suburb without a sales outlet nearby, fair enough. But realistically, how many tourists are in that category?
I also believe that one can purchase a card on line. (Although I have never tried).
There is almost zero excuse for not being able to get a card. The only person that should feel aggrieved is the person who has to make an immediate trip to Melbourne and so cannot get a card in advance, and whose accommodation is in the sticks where there is no outlet, and who arrives by road and no where along that road is an outlet. I do feel sympathy for these people.
As for the five dollar purchase price. That is a question of pricing, and just like all questions of pricing, you have to make a decision as to whether or not it is worth it. It may be that for some people, that extra five dollars means a taxi is a better option. So be it. I understand that everyone wants to ride as cheaply as possible...just as those same riders when they are taxpayers resent high taxes and prefer users to pay for services.
I suspect that some people will be happy with the present setup, and would complain bitterly if it were changed. So that the authorities are in a no-win situation here. No matter what they did in terms of charging or availability, someone would have a beef.
What I like about Adelaide is that we managed to build a workable card system in very short time and at a fraction of the cost of the MYKIs and Oysters of this world elsewhere. An outstanding performance of which Adelaide can be proud.