Yeah, @mary nailed it. My argument (reproduced below in case you missed it) is about why to make the clocks spring ahead in the spring. The reason to make them fall back again in the fall is so that sunrise doesn’t end up way too late in the morning (for us here in Portland it would be close to 9am at winter solstice if we did permanent DST).
I also heard lots of objections along the lines of lost productivity and increased traffic accidents caused by the time change. Those arguments could persuade me! But they’re not necessarily dispositive. Like I say below, having more time for evening activities in the summer is a big deal! And shifting all the existing schedules and meeting times is not remotely tenable.
(The point was further driven home for me today when I briefly considered proposing to friends/colleagues that if people preferred, we could move a regularly scheduled thing an hour earlier to keep it at the same body time. I then immediately realized that was more trouble than it was worth and of course it should just remain at its scheduled clock time. So if anyone still has the idea that we don’t need to change the clocks in order to save that daylight, I’m pretty confident you’re wrong! Whether it’s worth it to save that daylight is another question.)
Mainly I’m delighted by how sane the debate has gotten, with everyone acknowledging the various tradeoffs. My impression in the past was that people mostly treated DST as something profoundly idiotic that had literally no conceivable justification! Maybe my (counter-)ranting about this every year finally worked?
UPDATE 2022: No, here’s an example of the standard rant. I guess it’s just my social circles that are getting saner.