What better way to kick this off than talking about SNCB. Not only do the ticket vending machines not accept non belgian cards (like visa and mastercard), only bancontact, proton and coins apply here (no notes please), which in a country that most people are just traveling through, rather than settling in permanently, does seem to be rather counterproductive. To have a Bancontact or Proton card you need to have a belgian bank account.
However, recently the geniuses at SNCB got together and tried addressing this issue and after long deliberation, it seems, they decided to put up new ticket vending machines at Brussels airport, to cater to the crowd wanting to purchase tickets to Brussels, without access to Bancontact or Proton. So far so good.
After having been frustrated (and post getting my own bancontact card) listening to visting friends and colleagues frustration, I was really excited to see this new creation at the soon-to-be-finally-after-3-years renovated airport railway station, that I immediately went to try it out, only to discover that SNCB had decided to create a completely new vending machine that does not allow you to use cards at all, however, you can use both notes and coins! Which is not particularly helpful for those landing in an international airport from a non-euro country.
At this point I am expecting within a 5-7 year horizon, SNCB will have produced a new ticket vending machine, that allows you only to pay with international cards, no coins, no notes and no Bancontact/Proton. Just because that seems to be the Belgian way of doing it.