To put the problem another way:

A 28 hole rim always has spokes something like 4" apart. A 32 hole rim has the spokes maybe 3.5" apart. But if you skip a hole on the 32 hole rim, now you have an unsupported section of rim that is 7" apart AND has a big hole in the middle of that span. The rim would be very likely to break at that unused spoke hole because of the long span and how the spoke hole weakens it.

Wheelbuilding is not that cheap once you factor in spoke cost and labor. Hubs and rims are relatively cheap in comparison to the total cost, so please spend the extra bucks and replace your hub or rim. Front hubs are particularly cheap.