I am not directly the target market, no. And the throttling itself is an indication that the heat was designed/accounted for in the Pi's design.
However, to say that the majority of users don't need better cooling, and it won't cause problems most of the time, seems inaccurate. If you use a microSD card to boot/run the Pi, how many of them are rated for blisteringly-hot operating conditions 24x7 (many people using the Pi as a computer will have it booted pretty much all day and just turn off the monitor, or go to screensaver).
And I have already had one PoE HAT's PoE socket pop partly off the board when removing it from a Pi 3 B+. Partly due to stress of flexing the board, definitely... but that kind of tiny solder joint on a part that is stressed when making a connection is exactly the point of failure that may not be directly caused by, but is definitely not helped by thermal stress.
However, to say that the majority of users don't need better cooling, and it won't cause problems most of the time, seems inaccurate. If you use a microSD card to boot/run the Pi, how many of them are rated for blisteringly-hot operating conditions 24x7 (many people using the Pi as a computer will have it booted pretty much all day and just turn off the monitor, or go to screensaver).
And I have already had one PoE HAT's PoE socket pop partly off the board when removing it from a Pi 3 B+. Partly due to stress of flexing the board, definitely... but that kind of tiny solder joint on a part that is stressed when making a connection is exactly the point of failure that may not be directly caused by, but is definitely not helped by thermal stress.