I tried to measure Ronny's sub patterns a while back, I forget when, but maybe last year during the slide? Problem is I could not figure out a way to check that directly with public data that doesn't require manually reviewing sub patterns for all the individual games for multiple teams, which even I was never going to do. As a proxy, I measured average minutes per appearance for the top 8 or 10 field players on several MLS teams, with I think a couple of further tweaks to be slightly more meaningful. I'm pretty sure it showed we were right there in the pack and not much of an outlier. Maybe Soup is right and we mostly had early subs but that's not what I remember finding (but I don't know for sure and I'm not up to searching for it). I'm quite certain we did not tend to have unusually late subs as so many people assumed. But maybe my method was more imperfect than I thought.
At the end of the season or maybe offseason, I also remember reading multiple claims that we objectively had the latest average sub times in the league according to some actual solid analysis. But I couldn't trace the original source of this claim and figure out if I trusted their data and methods. Which is a long way of saying my knowledge of Ronny's actual sub time tendencies is worth little more than a shoulder shrug.
Beyond all of that, BklynB says (somewhat tongue in cheek) that the numbers don't matter, because we have more depth and should sub earlier than anyone. I dispute that we have depth on the back half of the field where I think we are thin. We do have more than average attacking options, but we also have some of the best first choices and you can just as easily say it makes no sense to have the best attackers in the league and play them less than anyone else plays their first choices.
As for yesterday, it's been pointed out that Keaton just got married like 2 days before the game and we have 5 games in 15 days but we also came off 3 weeks rest and rust and there are a variety of ways to handle that and maybe there's a Nick Cushing thought process that takes that off all of that into account instead of dissecting the sub patterns in individual games as if they were all stand alone events with no history or future.
Overall, I think soccer fans obsess over lineup and sub decisions for the same reason football fans do the same for run/pass play-calling and baseball fans do for batting order and pitching changes. I think they are all easy to see and easy to discuss and so people talk about them because it's easier than subtle stuff like in-game soccer shape changes by both teams, or offensive line schemes in football, which even if you see clearly it's hard to explain to a public audience which mostly doesn't.* So we talk about sub times, and especially like to blame them when results are not what we want. And sometimes they are to blame, and sometimes a coach has bad tendencies, but I don't think it is the case that it drives results nearly as much as people say.
It's once again the metaphor of the guy who looks for his car keys under the streetlamp because that's where the light is good, even though he's pretty sure he lost them down the block.
* And TBH, I'm still not all that adept at seeing that stuff myself in real time until someone points it out. I catch it sometimes, but not consistently.