Yesterday my tenants had a new washing machine delivered. The sillcocks
were leaking after they were turned off and back on the installer tried
to fix them but couldn't. So the tenant went and bought new ones but
could not get the compression sleeve off the pipe. I went over and then
I bought a compression sleeve puller at Lowe's
http://www.lowes.com/ProductDisplay?partNumber=120988-943-03875. I
removed the old sleeves, cleaned the pipes with 00 steel wool, and put
on the new sillcocks with new sleeves.

They leak. Maybe one drop every 30 seconds.

So I was thinking of soldering on sillcocks instead, i.e.
http://www.zoro.com/i/G4072695/?category=7210.

Is there some reason that this is a bad idea? Why wouldn't a builder do
this in the first place?

Or is there some way to keep the compression sleeve sillcocks from leaking?