These are definitely valid concerns, and I share many of them. On the whole, though, one can choose to have a better experience on Steemit than they can on other social media sites. I'll take the spam I see here over the advertisements filling my screen on Facebook any day, and as for Twitter and Instagram, those don't seem to be anything BUT spam and the desperate attempts of attention seekers to stand out.
I rather prefer the retro interface here as well. It keeps the focus on the content.
Sure, I'd love a more sophisticated editor, and the sooner they fix that broadcast error problem, the better. And I'd love to see the spammers go away. But by taking some time to seek out decent writers (or even interesting people who are poor writers) and by expanding and then pruning my feed, I honestly feel that my biggest problem on here is that I don't have enough time to read all the things I'd like to read.
And that's what I mean by having to choose to have the right kind of experience on here. It takes work, time, and engagement to make it worthwhile. But even without the financial rewards I have to say that I've met more interesting and engaging people here than I expected to.