Public salary range is an important factor in employer openness and honesty. Otherwise it’s like you come to the shop, see nice packaged juice with a label “Only Fresh Fruits” and no price tag, and another tiny text at the bottom “Ask at checkout”. Do you like such stuff? Or may be when you go to some software vendor’s website, like the product description, click “Buy” button, and see “Send us an email for quote”. I normally just close the page at this point, because I known they will try to squeeze maximum from me. I understand, people opinions may vary, but as you said, this is not the jobs website which allows employers to do whatever they want because they pay for ads. We have top Kotlin audience here (at least judging by the fact people explicitly come here to learn and improve their Kotlin skills), so I think they deserve more information on job postings.