Always a fun debate, thx Josh!
I think this discussion becomes much more interesting if you throw out the "hard to get out" idea. It's working from a negative, defensive, position in my opinion.
The quote you shared is nice and accurate,
I think there are benefits to flats beside, "easier to get out when you need to". flats feel more like you are just out playing in the woods, once you work out the skills and technique, you can feel very in tune with the bike due to the softer sole and bigger platform, foot out drifted turns are possible, and even if you don't get your foot out, the ability to "open" your toe and knee more into turns seems to make cornering in some instances better.
but, you are more connected and efficient on clips, you don't have to adjust position and work your foot position to hold the bike...
Pros and cons in my opinion,
I ride both, but this summer, I did a big climbing day (trying to catch dawgcatching, ironically) on my flats and my knees were super sore that night. I put my clips on for a long day the next day, (CRANK BROTHERS candy, w/ easy release cleat, by the way, best interface I've ever used, after breaking 2 sets of xtr's last summer!), and bam, no knee pain. So, I stayed clipped the rest of the summer, no knee pain, more efficient climbing, not quite a playful or moto style w/ foot out drifting...
The interesting thing for me is there is one place were clips are so much better, techy climbing... more clearance and power, but that is also where people are most afraid they might not get out if they stall out... The challenge for Josh to climb some techy CO climb is interesting, as I would bet anyone climbing that would say it's easier on clips than flats. If you have to fail... then maybe stiff soles with cleats suck.. That said, I'd much rather have a 1mph techy climbing tip over then a 15plus mph slip a pedal accidentally and go down fall... that is the defensive thought though, not the positive, what works best scenario...
I also ride smaller wheels and think e bikes should stay on motorized trails, so there you have it...
Cheers!
Wade