Lightwave doesn´t offer a tool for terrain erosion, blender and houdini does, though blenders landscape erosion tools are slow and tricky to use and perhaps crude, it´s at least something of an attempt to acheive some form of semi good erosions, but I am too newbie on using that tool and need to read up on it, same with Houdini which I believe would do a much better job.
So you are sort of forced to use other tools With Lightwave, while those mentioned may not need to for some basic stuff going on that is.
Additional tools like Gaea and worldmachine etc does those task best though.
Considering what Houdini was designed for at its core (despite what it has grown into), it's no great surprise that it would offer some type of toolset for terrain erosion.
Lightwave is hardly alone in not having native tools for terrain erosion. I think 3ds Max had a script for it a while back, but I don't think it includes a native toolset, even today. Nor Maya, for that matter.
Also, I understand your point... that Lightwave doesn't offer a specific toolset for this purpose... but does it follow that Lightwave can't be used to create it?
Earlier in this thread, another poster talked about the level of difficulty and made comparisons to creating great works in Paint and spoke to the question of why you would use Paint if you had a superior tool.
To a certain extent, that argument is correct; but not necessarily in this context.
For example; if I go through the process of creating erosion in Lightwave, I can guarantee the next time I need to create it, it will take significantly less time to set up because I've established the process. I know what I'm doing and how I can do it.
Each successive time I have to set up the same simulation, the set time will be decreased... it becomes de riguer.
Even when you are given a specific set of tools to design an erosion simulation it doesn't follow that an individual will immediately be successful. The measure of success will depend on their relative familiarity with the tools.
Even robust tools can get odd or poor results.
So tying the original question back to your erosion example, I would say that it is entirely possible to create an erosion simulation in Lightwave.
Is it easier using a different software, especially using one created with this type of simulation in mind (like World Engine)? Most likely it is.