I would not put it as bluntly as above, but I do agree with this. Swedes generally have very good English and they usually love to practise their English. This means that when they hear me speaking Swedish with an English accent, they switch to English. I know I am not alone in this as it is a common theme in Swedish subreddits.
At first I was insulted, feeling that the person speaking English in response to my Swedish felt my Swedish was not good enough. But afterwards, I realised they thought they were helping me, and were happy to have a chance to speak English. Nowadays when people do it, I just continue speaking Swedish.
The good level of English in Sweden means that many English speakers do not feel they need to learn Swedish, particularly if they work in English. You can get by with English, but there is no escaping the fact that Swedish is the language of the country. Authority voice messages, official documentation, voting slips, dealing with the system, shopping websites – everything is in Swedish. Of course translation programmes do help, but if you are planning to live in a country permanently, it does help to know a bit of the language.
I had a friend once who had been in Sweden for 16 years. She did not know any Swedish. After 16 years she noticed her large group of friends were not inviting her to dinners or events as often. When she asked why, they said that after 16 years, they had become tired of all having to switch over to English for one English-speaking person who refused to learn a word of their language. She was very upset, but I do understand. It would have meant so much to them if she had tried to learn a few phrases, or to understand better so they could speak Swedish sometimes and she would understand. No one has to be perfect, but knowing a few phrases shows that you tried.
Not everyone is good at languages, and I am lucky in that regard (though I am hopeless at maths). But I spend my life helping Swedes speak to others in English. It does not seem unfair to expect people living in Sweden permanently to learn a little about the language and culture of their new home.
I agree with you, when I lived in the South of England I used to visit France at least one weekend a month so learned some French. Those who understood English appreciated my attempts to speak their native tongue and those who didn’t were happy to speak to me in French, correcting me where necessary.