I think aiming for having all materials and currencies be valuable is a good goal. What I don't understand is why they locked on to weapon parts rather than planetary mats and glimmer, which we're drowning in. (I've never dipped below 20k glimmer since TTK came out; going on a synth buying spree tonight.) Just odd.
I feel like the weapons part nerf falls into the false idea that guns in this game are 'balanced' in any way. If guns were balanced then I could see how having less options might make it seem like the one you have is more 'valuable' but that's not the case. Most guns are just better or worse than others. The focus on PvP at this time also exaggerates it a little at this time. This is one reason the weapons part nerf hurts so hard, having the right weapon makes a huge difference and you can't make the other weapons more 'valuable' just by making the good ones harder to get and level.
However what frustrates me the most with this idea that sticking you with whatever the RNG gods blessed making them more 'valuable' is that comes at the cost of being able to try out different playstyles and diverse setting which is much more fun.
My biggest disappointment in post TTK patches is that they are actively making diverse setups harder to get. The 3oC nerf, strange coins nerf, weapon parts nerf all feed into having less options available for each player. I don't really think this makes any player 'vaule' whatever RNG gave them more. It's just frustrating and creates a capability gap because of the inherent gun imbalance I mentioned before.
When TTK launched I had hoped that collecting and creating diverse loadouts might be the endgame focus now. The game has enough content that just getting one of everything and leveling it up to be useful will keep players busy for a long time. I would prefer to see things like kiosks for unique legendary weapons made available and having the tools to build up your own collection you can value and look back on. Give players easy options to collect and level many weapons and they might create more diverse loadouts than we're seeing under forced scarcity which promotes a laser focus on weapons the community has already deemed useful. Most people now simply won't be able to try out anything new without grinding they don't have time for.
Unfortunately the focus has been on decreasing player options and a much higher reliance on RNG, thae adding 'value' to that RNG by removing other options. I don't think it's interesting for the player or needed now the game has grown.