Still can't quite figure out his variance between people at Disney World during the exact same time with two completely different experiences....things that make you go hmmmmm
I can give some insight. We have been to WDW many times when crowds were generally very low, and times that were busier. There are a few examples, though, of how a temporary spike in standby times can affect the perception of crowds:
1- We had a fp+ for Soarin' at around 5:30pm. When we entered the line, the standby time was 20 minutes. There was a problem with the ride (still not sure what happened, but a delay) and we ended up at a standstill for almost an hour before boarding. When we exited, the standby time had swelled to 80 minutes. Someone walking up then would have no idea that the wait was much longer than the "norm" for that time.
2- We arrived at Nemo ride entrance one morning, and the line was over 30 minutes!! I have no idea why it was so long, but within an hour, it was back down to the normal 5-10 minutes and stayed that way for the rest of the day. But a guest walking up at that time would have seen the line and thought the ride was always super crowded.
3- We got to DHS for rope drop and ran to TSMM for a FP. The place was swamped and crazy. We returned at our FP time and rode. As we exited, the standby time stated 50 minutes, but we were able to get in the standby line and get on the ride in less than 15. Why? The standby times are almost always waaay overstated at TSMM. The CM at the entrance told us to come in because there was no line at all at the time. Again, a casual visitor walking by would have seen the standby time listed and thought the line was outrageous.
4- There are funny crowd spikes that affect certain attractions temporarily throughout the day. Haunted Mansion times can go up dramatically when a large tour group all enter the line at the same time. Same with some rides in the MK as soon as the parade or Wishes is finished.
Seems like timing can really affect how busy people think the parks are. An unlucky family can just get in line at the wrong time for a few attractions, arrive at the parks the wrong time, try to ride attractions during the middle of the day, and decide the parks are swamped. Another family can go to the same park on the same day, luck into really short wait times for a few rides, eat meals at off times, and take advantage of knowing when to ride the big ticket attractions, and have a great experience.