This is a good news for Europe.
But I don't quite understand why they do it, they see big opportunities in what exactly? It is quite unclear at least for me.
In Indonesia there is no bank that officially supported buying or selling cryptos, we used a third party (exchanger, to be exact) to buy and sell crypto. After that, we exchange it with fiat currency and then transfer the money to our own bank account. Because there is no strict regulation on cryptos (Indonesia's government are "learning" about blockchain tech they said, at the same time there is a plan to launch Rupiah crypto with a flat value just like Indonesian fiat currency), this practice is still on going till today.
Opportunities to attract new customers.
It's the same reason Overstock enabled bitcoin back in 2014 - they were losing their competition with Amazon.com, and used bitcoin to gain publicity and get new customers. It worked, loads of bitcoiners who hadn't even heard of Overstock signed up and bought stuff from them.
Banks are working on a very competitive market. They're 'only' dealing with money, they're not producing anything that can be labelled differently etc., they just doing nearly the same service to customers to let them use their money.
If you think about how you choose a bank, what's your first thought? The logo, the color of the bank, the stories you've heared from other people about that bank? Do you think about any 'product' of the bank? Not really, because you can open a bank account at every bank, and every bank charges you a fee if you use their services. No difference. Only the marketing and the trust that can make difference...
If you're an old and big bank like Barclays, you have the trust, you are not forced to overuse marketing. If you are a smaller bank and want to grow bigger, you have to make yourself different. If the basic services are the same at every bank, what can you do to catch the attention of the customers? Doing something special, to make them think about you (the small but special bank) at first thought if they hear the word e.g. bitcoin in this case of Fidor.
Do you know a bank that's friendly with bitcoin? Now you know, and that little bank has made itself different, which can help them to acquire a lot of new customers who are interested in bitcoin. (And that can help them making more profit, and the possibility to grow).