Maybe for some people, but I couldn’t disagree more. I always thought it was quite the oversight to have a game that seemingly prides itself on having 255 colours for every block and then making it so that, for most of them, you can only ever have a tiny amount (to brag about) in your colour storage, and not use them for building, which is arguably the strongest appeal / feature of the game. Always felt like it was intentionally handicapping itself. 
Don’t get me wrong though, I’m a collector myself so I get why collecting (rare) things is fun, but colours was always a very bad choice for that (at least in my mind). They could’ve added collectables specifically for that purpose and maybe pair them with interesting mechanics to obtain them 
While I’m not the biggest fan of gleambow racing myself, I doubt most people saw it as a good way to stock up on blocks 
The sacs were always the main attraction for me 
By the way, I think it’s silly to be sad about unlocking the colours. What was lost? Bragging rights for the people that have a couple of red pieces? Pseudo exclusivity for white stone that just makes people stop playing because they started their builds with them and ran out? Can’t speak much to the economy aspect of it all. Never really liked it. Always felt like we are shoving systems that are f-ed up in real life into games in the hopes they work better there. 
This happy little accident is a net win for me, but I guess we just have to agree to disagree
I’d also vote for just unlocking all colours, but at the very least doing this would be nice: Unlock the colour palettes of new sovereign worlds