I agree Backlinks and Content are both equal in importance. Yes you get both good quality and poor quality of both. SEO will be here for a good while and these will be part of the web traffic tools.
For me it's backlink. You can have the best content in the world but you won't have anyone reading it if it doesn't rank and to rank you need backlinks.
Def, you need "meaningful" & "engaging" content on your website so your site visitors can understand what your site is for. You also need a bundle of good quality content for reasonable website promotion & that content should relate to your target market.
I've always thought that the Search Engine Optimization industry is shady. There isn't much practical benefit to moving your site from number 1,000 on Google to number 500, because no one looks past the first page of search results.
The most important thing for any website is the user. Before a site can become popular, you have to make it useful to someone, which means adding good content. A website won't promote itself of course, but SEO is not an effective means of promotion for a new site. I would recommend promoting it through more conventional methods, and letting backlinks come naturally as people start using the site.
Both are needed to succeed in any competitive market and as long as you are supplying great content that people want to read and link to, and your sharing your content/site/pages in the right places you should earn links naturally without having to build them all.
For example, if you was to share news of your new post on other relevant sites and people like what they read, they are likely to talk about it and share it. Another great way to get people talking about and sharing your content/link is via social networks such as twitter and facebook.
But yes, the bottom line is, without sharing your content in some form, it will not gain links, which means it will fall behind other that also have good content but are out ranking you because they are getting it to more people and are building and/or earning more links.
Content is king, but links are the kings prawns, and what's a king without his followers?! Nothing, because without them the king is no one