So you can count me as one of the people who's been staunchly Bitcoiin-maximalist for *years*, but is now questioning Bitcoin's direction in a fundamental way that I have not before. There hasn't been an event in Bitcoin, until now, which threatens to fundamentally change Bitcoin's longterm vision and key value. So it's pretty darn reasonable for people to start looking elsewhere. I personally haven't converted any cold-storage BTC to alts, but as you note, I'm seeing long-time Bitcoiners do so (or at least talk about it) for the first time. Core and supporters may want to take notice before the reality that Bitcoin is not operating in a competition-free vacuum hits them in the face. There's still time to fix this. But not much.
The Monero devs are working hard to perfect Monero so that it is ready to fulfill the initial vision of bitcoin, before it was taken over by money interests. Back when Bitcoin was supposed to be anonymous and the community was full of people who were interested inthe technology instead of just getting rich fast.
If BTC fails to adapt due to these conflicts, the long term bitcoin community will be able to choose between stuff like ETH which is an ICO premine that might not even work, or they will be able to choose Monero, and it will be like Bitcoin in 2010 again, except that there is an adaptive blocksize, tail emission so you dont have to support the network with fees alone, and true privacy, so coinbase doesn't shut down your account for spending your bitcoins in unapproved ways.
I hope for the future of crypto and the world that we choose Monero.
Right now its easy for a former bitcoin maximalist to get into Monero and hedge this possibility. Just .3% of your BTC and you have an equal stake in Monero. Or you can go bigger and increase your overall stake in the scenario that Monero succeeds. By the time most bitcoiners realize that this is something they need to do, it will be much riskier and cost them a greater portion of their BTC to hedge.