The Netherlands is in the EU. English is the most widely spoken language in the EU, even after the UK left, because it is by far the most common second language. Nearly half of the people in the EU can speak it.
In Northern Europe the percentage is even higher. In the Netherlands there are almost as many people who speak it as there are Dutch speakers.
Taking into account people from other EU countries who are there on business plus tourists there is a good chance that if only one language was to be used for train announcements more people on the train would understand if it was in English then if it was in Dutch.
The Dutch were ridiculously bad at imposing their language on other countries. Little trace of it remains in Indonesia, or New York. Aruba, Curaçao and Sint Maarten have never taken to it. South Africa is kind of the exception except even then Afrikaans has played second fiddle to English for 150 years, and they have sought to differentiate their language from Dutch in more recent times.
Portugal has been better at that game when you consider its size.
It already is, mate. There are people who move to countries such as the Netherlands, Iceland and Sweden and insist on using English all the time. I've even heard of Dutch using English with each other. There are people who've attempted this in Spain, but it's harder there since there are so many Spanish speakers.
Every language has strengths and weaknesses. Perfect is the enemy of good. If your definition of 'good' is 'relatively easy and technically international', Esperanto is very suitable. (Not to mention way better than the status quo, in any case.)
Ideally announcements should be bilingual, but if there’s only one language, it’s better to inconvenience any number of foreigners than even a single native who doesn’t speak English.
The point of an official language is that the government makes it as convenient as possible living your life knowing only that language. It wouldn't be that unreasonable IMO to switch official language to English, but seeing as NL is a democracy, that ought to be a democratic decision. A referendum of some kind would probably be best. It's not a small decision to be taken lightly.
But it's still nice to offer information in other languages in certain situations. Infrastructure used heavily by tourists and recent immigrants who don't speak the language yet should be made as usable as possible to people who don't know Dutch. Making important announcements in both English and Dutch on trains is an example of that.
Yes, I'm obviously not mad with them using their own language, and I am studying it since I live there. But it's in the EU, and there is a lot of international tourists on the train, who shouldn't be expected to learn the national language of every country they visit just to navigate it.
Yeah, why bother using their own language at all? They all speak English and are just pretending. I want all the people in all the places I visit to be just like me.