TBH, just copy paste EVE skill tree; it was misinterpreted to begin with.

"You have to specialize" is a phrase I hear a lot, but it was actually originally just a piece of new player advice (one created by players, not devs). This was also misinterpreted; we are locked into our choices (unlike EVE, where you build upon your choices to diversify your range of specializations). This piece of advice originated from the fact that there are only 5 levels for each skill in EVE, and as such a newbie can hit the veteran efficiency plateau faster by picking something specific, then you expand from there and branch into specializations that have some skills in common with what you've already trained. It was not meant to convey the message that "you pick one thing and that's all you ever do".

DUST fails at this; if you want to diversify, you often need to go all the way back down the skill tree and start from scratch.

Case example:

In EVE: Small Autocannons and Artillery use the same source skill: Small Projectile Turret Operation. It's first at Tech 2 that you can 'specialize', and even then it's only one skill (e.g. Small Autocannon Specialization). Specialization here is as broad as "I'm good at using small projectile weapons". You can then build on these skills to reach medium sized guns. A specialization in Small Autocannons includes skills that aren't linked to Autocannons specifically; such as Rapid Firing (which benefits all turrets). And importantly, deciding that you want to do Hybrids instead of Projectiles conserves the usefulness of the SP spent on all but 2 skills in this case (Small Projectile Turret Operation and Small Autocannon Specialization). Finally, all of these skills are worth training to 5 in the long run.

In DUST: Each weapon has 5-6 skills that only affect it. Want to train a different weapon? What a shame, none of those skills apply to others, and you'll have to train those 5-6 skills that do the exact same thing again. Each requires multiple million SP invested. A specialization in a given weapon is entirely within the 5-6 skills that that were added with that weapon, and 'belong' to it. Finally, some of these skills aren't worth training to 5, while others are mandatory to 5.

Unlike EVE, where the vast majority of skills help you towards your next specialization, DUST has a system where the minority of skills are useful beyond a specific piece of equipment. This creates a sense of "SP sinks".

So it bares repeating: the important part isn't if it looks like a tree or not; the important part is how much SP (player time and effort) is locked into a given specialization, and therefore how much SP is to be considered "useless" when chasing a new specialization. The more SP is useless to any other specialization, the less people will diversify, and the lower the actual depth of the skill tree becomes.

Compared to EVE's; DUST's skill tree looks like one you'd find in a theme park game. And it's not for a lack of skills, it's in its structure.

e: We used to have a size specific blanket system, but that wasn't implemented very well either (we still had operation skills for specific weapons rather than size and type, and the blanket skills were size specific). Uprising was a step backwards w/ regards to the skill tree.