Translator: You're bad cause you complain about free stuff.
Reader: No, you're bad for hitting everyone cause of a vocal minority.
Me: You're both idiots.
Pretty much this. Although to be fair he WAS being slow, he was like months behind. I personally didn't care enough to complain, but some people did i guess. While the slowness isn't bad or "wrong" in itself, sometimes it can be a problem for a popular series because most scanlators try to avoid "sniping" series that other people are doing, so you kind of hold a series hostage when you do that. But longer delays every once in awhile isn't bad, of course IRL stuff can happen to you causing delays. But when you hold a series hostage, and now you delete everything on top of that for a few "very mild" comments complaining about your slowness (which was true), it makes you an asshole and a baby on top of that.
In my job in the real world I work with alot of clients, once in a while there will always be complaints of slowness or lack of quality or blahblahblah, and the comments you can get IRL can be much worse and more personal than the "very mild" comments from that chapter. And sometimes when I get complaints about slowness or lack of quality I agree with the clients, but for one reason or another it is how it is. Either I'm sick and being slow, or I lack certain tools to make the job easier/faster, or lack of budget to make the job higher quality, but there have been some occasions when I understood the client's frustration. But you can't let it affect you mentally in that way, you just do the best you can and move on. As long as you do the best you can, you can never go wrong, it's important to think like this so certain negative comments don't affect you.