Disclaimer: I'm a PM on PowerShell at Microsoft, and the following is based on my personal observations. There's also no current plan to do any of what I suggested (but it's certainly giving me a lot to think about at the start of my work week).
The default ExecutionPolicy was engrained and controversial long before I joined the PowerShell Team (or even Microsoft), and I'll be the first to admit that, as a long time Linux user, I didn't GET why I couldn't just run arbitrary scripts.
The public Microsoft opinion on the matter has always been that ExecutionPolicy is there to try and prevent yourself from shooting yourself in the foot. In Linux, this is very similar to adding a +x to a script (although that's clearly much simpler than signing a script).
I'd say it's also akin to the red browser pages warning you about self signed certificates, or Microsoft/Apple "preventing" you from running certain app packages that are "untrusted" in one form or another. In one sense, you could actually argue that PowerShell was ahead of the curve.
Now as a power user with much less at a stake than, say, an IT administrator at a Fortune 500 company, the first thing I do with all these restrictions, warnings, and confirmation prompts is to turn them off.
But those warnings (often with no clear way to disable them) are there for a reason. PowerShell was built at a time when Microsoft admins were GUI heavy, and PowerShell did its best to herald them into a scripting world while fostering best practices. And if you're using a bunch of scripts sourced from SMB shares within your domain as a domain administrator, you don't want to accidentally run a script that hadn't gone through your internal validation process (hopefully culminating in the script getting signed by your domain CA).
So let me assume that you agree with everything so far. Why does this experience still stink? Any Microsoft administration worth their salt uses PowerShell, and many of even the power-est of users finds ExecutionPolicy annoying.
In my opinion, it's too hard to sign scripts. We should be following in the footsteps of the drive to get everything on HTTPS (props to Let's Encrypt and HTTPS Everywhere, along with many others). We should have guidance on signing if you have a CA, we should have guidance on getting scripts signed by third party CAs, and we should probably offer a cheap/free service for signing stuff that goes up on the PowerShell Gallery.
Oh, and we should make it easier to read the red error that gets thrown explaining how to lookup a help topic that tells you how to bypass/change ExecutionPolicy.
Unfortunately, that's all easier said than done. But the default being what it is puts the onus on us to do something to make security easier.