When a few months go by without a significant improvement to usability, interest will wane.
There is this crazy little thing called a brand new written-from-scratch-with-extensive-usability-testing GUI that was revealed last week to rave reviews and while a release date has not been announced more than a few months not a very good guess.
Personally, I'm watching Monero very closely.
Seems unlikely given that you didn't know about the GUI.
I'm less concerned with a GUI and more concerned with bloat. A GUI is a trifling thing compared to that. You want applause for delivering the most basic thing that a cryptocurrency could have? When I said usability, I meant real world practicality. Even if you guys released a perfect GUI tomorrow, I wouldn't shift my investments just for that.
Bloat is irrelevant for years and you know it. The blockchain is currently growing at about 5 MB per day, or 1.5 GB per year. That is nothing. As usage increases, this rate of growth will also increase. If Monero grows twice as fast as Bitcoin then it will be the current size of Bitcoin in terms of volume and 5-10 times the current size in terms of blockchain. That is not now, not next year, but 3 years from now. That is entirely manageable. Moreover, most users will likely be using thin clients and web wallets. If your claim is that full nodes running in datacenters and on VPS (and probably some enthusiasts at home) won't be able to handle a 100-200 GB blockchain in 3 years you have completely lost it.
Also, the GUI is hardly the most basic thing. It is probably the more carefully and professionally designed GUI that has even been developed for any coin. What other coin GUI was developed using formal usabililty testing? Certainly not the 99% that are copy-paste Bitcoin-qt clones, and likely few if any of the other 1% either.