First the operational reason - holds are sometimes used for course
reversal on approaches in lieu of procedure turns. In such a case,
you are expected to do only the hold entry. Further, for your own
good you need to be well established on the inbound course before
crossing the fix. Finally, when this is done, the reason the hold was
chosen over the PT was to keep you out of airspace or obstructions.
So the bottom line is holding is not important until it it. Still,
there are other items that fall into that category (for example IFR
departures from VFR fields) that are not covered at all.

Good point, screwing up an enroute hold is rarely a big deal, but IFR
departure procedures often prescribe identical orbiting procedures
(even if they are not called "holds") that really do keep you out of
the weeds, sometimes with not very big margins. If you get messed up
there, I'd say head straight back to the navaid while climbing and try
to sort it out.

I only became really aware of published IDP's and the various TERPS
issues after reading Wally Robert's site, my own instrument training
did not emphasise this too much, which is a bit scary in retrospect...