You can sort by recently replied to view a version of the boards that's bumpable. Generally the reason we don't globally like bumping is because a huge part of this platform is a focus on relevance.
We believe that the default view of the boards should be the one that is most relevant for viewers so as we build and optimized systems for visibility we are going to do it from the perspective of - how can I make the first few pages of content fresh, relevant and engaging for the person who is reading them.
That naturally means that the balance of influence between the viewer and the poster has changed from forums - where the viewer experience is becoming more and more important which means if the poster wants visibility - the burden is kind of on you to make content that has appeal to others.
The amount of content that gets posted every day (2000~ discussions, and 10k~+ total posts) is far too many for an individual to read through so naturally we're building some methods to prioritize and show people what they're most likely to be interested in. The system is really in its infancy though so I expect over time we'll be able to make pretty substantial improvements