The FAA is taking action on the bogus NOTAMs closing airports to diversions, international diversions, unscheduled operations, etc. Example:
AP CLSD TO DIV INTL AIR CARRIER ACFT EXC EMERG ACFT AND DIV INTL AIR CARRIER ACFT 3HR PPR XXX-XXX-XXXX
This undoubtedly presents a safety issue to our profession, and for the PIC when holding/contemplating diversion and this or similar NOTAM gets issued for your alternate(s). Sometimes these have been issued prior to a weather event happening. Crews can still declare an emergency and land at the airport they wish to.
While yes, gate/ramp capacity can be an issue especially after several planes divert to one airport. I do speak from experience on that as I used to work at the airports prior to dispatching. However waiting for a parking spot or fuel or whatever it may be is a lot better than being in a low fuel situation in the air. Not every airport within your fuel range will be a viable alternate.
Hopefully this leads to some change and provides a higher margin of safety.