I've had this thought myself before.
With the Aluminium ones for jointing wires mid-span, I don't trust them.
I'd sooner use a double ended crimp sleeve, with the proper hydraulic crimper.
Having said that, we have thousands of them IPC things at work and most of us guys refuse to use them.
After all we didn't buy $$$$ crimp tools for the sheer fun of it.
If you could ASSURE me that the point contact resistance was the same for an IPC connector over time, I wouldn't have a problem with using them, but in all the failures I've seen with them, it's been because the connection has not been tight enough and has burned itself to bits.
Any shear-bolt system needs to be well tested before going on the market, IMO this hasn't happened.
Let's face it, these days if you're not young, you're old - Red Green