This is a pretty extreme and entitled position. You're the one assuming that the website will offer you something of interest without any reason to do so, and that you should receive it however you want (without ads). If anything it's more reasonable to assume that you'll see ads on every page you go to.

I take the complete opposite position: if I take the effort to make a website, I'll do what I want with it. Maybe I consider your visit an attack on my bandwidth, and I compensate with ads. If you don't like it, you're free to not visit it. Unless I told you in advance that you're not going to see ads, there's no basis for assuming that there won't be ads just like there's no basis for assuming you won't see NSFW content on a random website, religious content, political content, etc