I know MyBB, phpBB and few softwares don't have in-built SEO and sites using these softwares are doing well in Search engines. So is SEO not about the Link structure, tags alone it is beyond that?
Content is the King. Otherwise, I do not know how those old vB forums are still getting impressive traffic. MyBB latest major release was at least 3 years ago. There are many busy forums that used to run MyBB. It is possible that Google has means to understand popular CMS and adjust itself to it.
In MyBB's official community i found few big boards and they still are powered by MyBB and they are getting massive hit. As you said Content is a key and targeting right users will surely help i think
Jason Content is a key and targeting right users will surely help i think
Select a few topics and write like crazy about it. One day, everything will be based on those data.
These days, social bookmarking is also helpful.
I will be blunt of this. Only a handful of forum software has reliable SEO. Some are vintage, some are ignorant and some don't care.
WordPress has a no. of SEO plugins. Forums can have them too. I have seen people who offer to do SEO for your forum with proven stats. That is also a good for webmasters than relying on the software alone.
If you are using a SEO plugin make sure that they will keep it updated for a good period of time. A plugin that becomes old in a year or two will do more harm than good.
No, I don't like being abandoned in the middle as well. That is why core SEO is very important. Luckily, every CMS tries to do that, whether they suceed or not.
Using something like Google SEO plugin for MyBB is preferred. Lot's of forum softwares have their own SEO-enhancing plugins you can use for friendly URLs, easier crawling, etc. Other than that you should be focusing on releasing quality content and keeping your community engaged. You can easily rank long-tail keywords with forums and blogs.
Aces Hmm but i see few big forums don't use Google SEO Plugin for MyBB. But they do offer quality content and support through the forum which helps them to rank better.