Indieweb seems like a good alternative if all you want to do is publicly post your bookmarks. I would definitely use my own website if that was all I wanted to do.
To me a service like Pinboard – and previously Del.icio.us and Diigo when it was free – is a search tool. Browsers do not offer the facility of searching your bookmarks beyond the words on the page’s title. With a service like Pinboard, I can save the links I really need from my Google searches and tag them, probably with the same keywords I used to find them in the first place. Later on, I always know where to find something, I only need to remember a few keywords. It’s like having your own personal Google.
I use that in combination with Instapaper and Evernote. If it’s something worth keeping I’ll save the whole page to one of those instead. If it’s purely a filtered search result from Google I’ll save those links to Pinboard.
I’m quite happy to pay a little bit of money for that service. As you said yourself, they are less likely to go bust and disappear with years of your personal data. Which is why I was so desperate to get my data out of Delicious. I won’t get caught off guard again.