I feel with you Mike Jacoubowsky!
My few waitlist experiences with UA have been less than pleasing. Most likely also because UA - in stark contrast to the Star Alliance propaganda - does only partially honour the status priority.
All this became possible because of the abominable WX excuse. As long as weather related excuses allow airlines to walk from their obligations and unilaterally abandon their duties, these things will never be rectified.
The silly attitude that WX equals force majeure promotes bad planning on behalf of the airlines, a small cloud is an amnesty for all planning related mishaps later that day.
If airlines were held fully liable for WX delays and overnights, the incremental cost would initially be added to the ticket price and hence be neutral over a large number of flights. But it would then honour good planning on behalf of the airline as this would then lower their WX related expense.
I find that ever since the EU carriers became liable for overnight and meal costs in WX related delays, they became a whole lot more proactive with routing us to the destination.