I agree with this to an extent. The "spirit" of Terraria that the developers talk about isn't going to change, but there are minor quality-of-life elements from starbound that I wish were in Terraria. For example:
1. using the same block for both foreground and background makes building SO much more efficient, and using left and right click to place (and destroy) foreground and background blocks was extremely intuitive for me.
2. Speaking of right clicking, making use of right clicking in general is something that Terraria could easily adapt from Starbound. I wouldn't want Terraria to directly copy Starbound's right click special move system directly, but some way to make combat more dynamic instead of just dodging and left clicking would be nice.
3. Collections. A collections tab was recently implemented in Starbound, and I would love Terraria to have a collections system. Give us some reason to go underground and explore! Once I've collected enough ores/gems/treasure chests I rarely go underground in Terraria. Do I need a tenth pair of Hermes boots from another gold chest? Do I need another cave bat banner? Perhaps my 1,000th gold ore or my 200th diamond? No. I'd like ultra-rare goodies underground in Terraria that only the most dedicated players will find, even if they're only decorative and serve no purpose in combat.
Even better, introduce an NPC (like the angler) where the player can trade in extra-rare treasures for exclusive goodies (although skip the daily quest element, that's a pain in the butt). Certain items are already fishing exclusive, why not introduce treasure-hunter exclusive items? It might actually give me a reason to go spelunking in hardmode again instead of playing a glorified tower-defense boss killing game in hardmode.
This is slightly off topic, but my number one complaint about Terraria is that the spirit of the game changes from pre-hardmode to hardmode. At first, finding a new treasure chest or ore vein in a new world gives me a rush, and this sense of exploration is completely absent from hardmode. There's nothing wrong with the combat emphasis of hardmode, but I wish it wouldn't come at the expense of the exploration element of pre-hardmode.