As someone in an English-speaking country, I expect my colleagues to have good English.
We operate a helpdesk where clear communication is essential. Internally, we need to be able to quickly coordinate with each other on highly technical problems. If someone from another country came in with a bad attitude about "why do I need good English?" we would be more than a little hesitant about hiring them. It doesn't matter how good you are in tech, English literacy and fluency are foundational to everything else.
It would surprise me if Germans see this very differently.
It IS different in non-English speaking countries. I live in Japan and work in an English workplace. The harsh reality is, if you want to hire talented in-demand people from outside your country, and your country's language isn't English, then you have to accommodate English in your workplace.
If you insist on using your local language only, then you will only have applicants from your own country: very few qualified candidates living outside Germany(/Austria) or Japan can speak those languages at a highly proficient level. If you have no need of importing professionals from abroad, that's OK; obviously it's easier to recruit people in your own country if you stick to your country's native language. But if you have a big talent shortage (as is typically the case for the tech sector), then not accommodating English will mean you can't compete against companies that are more international (i.e., they use English).
Like it or not, English is the most commonly-spoken 2nd language in the world; it's the international language of business and trade. College-educated professionals mostly all speak it these days. So if you want an international company, English it is.
We operate a helpdesk where clear communication is essential. Internally, we need to be able to quickly coordinate with each other on highly technical problems. If someone from another country came in with a bad attitude about "why do I need good English?" we would be more than a little hesitant about hiring them. It doesn't matter how good you are in tech, English literacy and fluency are foundational to everything else.
It would surprise me if Germans see this very differently.