Now, as a web developer I understand the aversion to changing something that has already been put in place. But I also know the benefits to user engagement. That's what the internet is all about. Keeping people engaged, whether it be with your product, or in this case with each other (and your product)!
To put it bluntly, I find this old style forum to feel a bit dated. It lacks some nice features that have come about in recent years.
Has anyone used a Discourse forum before? You can set one up for free and has all sorts of handy features that keep people engaged and informed:
When it's a user's first post, reminds you to welcome them.
The default tab can be a nicely laid out list of all threads across all categories. Very helpful for visibility of threads within lesser traveled categories.
Built with a mobile first mindset. This current forum is a bit tedious on mobile, which decreases user engagement.
Images and Embeds are more seamless -- less clunky.
Uses ajax. Make posts and watch them update without refreshing.
A modern post editor
Badge system, may be gimmickie, but really does keep things lively and fun.