wrote:

2. Why cant someone just use a common hose clamp? Hose clamps are a
tad bit more costly for the actual clamp, but the average DIY
homeowner is not going to spend $100 (or even $50) for the tool to do
one job.

I think it's because those clamps don't apply even pressure all around
the hose because the clamp is distorted where its screw fits. It's
also possible that their screws work loose (one brand of clamp had a
screw lock to prevent this). I have a heater hose fitting on my car
that's a lot more likely to leak when I use a screw hose clamp rather
than the factory flat spring steel clamp, even though the latter
doesn't seem to clamp as tightly. Also I've read that air conditioner
hoses for cars have to be crimped for systems that use leak-prone
R-134a refrigerant rather than the old and now-illegal R-12, and one
FAQ about making those crimp connections recommended actually
measuring the crimps every 60 degrees with a micrometer o make sure
they were perfectly round. Sure, household plumbing connections
aren't the same as A/C or heater hose connections, but then the latter
two aren't buried underground or inside walls and aren't expected to
last decades without maintenance.