I was looking into planning a train trip with a friend from abroad and I realized that getting a Rail pass for him would be a lot more expensive - 371 EUR vs. 253 EUR.
Is there a reason why non-European residents are heavily penalized? Or perhaps the two passes aren't actually fully equivalent?
The reason is more likely to be historical, rather than a practical difference with the two passes. As a matter of fact, Interrail used to cover more countries than Eurail with Great Britain being the difference. But as of 2020, the UK is part of Interrail and Eurail, and both programs cover the same 33 countries.
The Eurail-plan was started in 1959 as a way to originally get American visitors to visit European countries. Interrail on the other hand was started in 1972 and originally it was only available for the European youth under 21. Since then both passes have changed a lot and only recently since 2007 have they been sold by the same company. Essentially they started as different products with different purposes during different times.
Currently the prices for Eurail and Interrail appear to be the same (source: Eurail/Interrail website). So the question is now moot.
