The bottle-neck is the marketing here.
The btc bagholders need to be told about Monero.. I am quite sure there are many who have not even heard about XMR.
No, the bottleneck for a lot of bitcoin bag holders is probably the GUI. They come from BTC, where they have a plethora of GUI options (and hell, wallet service options), and then they see simplewallet and mymonero and go "you serious?" and hell, up until 4 months ago (so, the entirety of almost the first 2 years of the networks existence), the released binaries required all the ram.
I doubt they haven't heard of Monero. They've probably heard of it and dismissed it.
I see your point, the lack of GUI is something that may not attract people towards XMR. BTC is already quite mainstream (and ETH is hitting mainstream big time as well - XMR can be the # 3 coin and the ultimate store of value).
However, mass adoption takes time. People will begin the adaption process by ignoring the new way of conducting businesses, then they might experiment once they have been bombarded and finally they are going to adore it.
The good news is, the current price trend should incentive GUI development process as the value of the bounty grows.
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