What is a bad player to me? Oof, I don't like this kind of definitive sort of question. I don't want to call someone bad for one or two things they've done, and most of the time, it's not like I can comment on how they do after I encounter them, or even before that. Yes, something they do may be less than brilliant, but it doesn't mean they are, in themselves, a "bad player".
I could group people up and put them in boxes, but I don't feel it's right for me to do so. I just can't damn whole sways of people I don't know. What I can do is gauge my own personal experiences, and although it's just anecdotal, that's what Tales from the Duty Finder is for. The best self-help thread I've seen on a game forum anywhere.
So, if in one particular instance there's someone who seems to not be pulling their weight, and even after kind words nothing seems to occur, then I might vent in that thread, or to Hubby. That doesn't mean the person pulling their weight won't then go and have an epiphany at some point afterwards and suddenly become the most attentive player ever. I'm likely never to know if that happens or not. But it could. I only know that if I didn't try to help them help themselves if or when I can, then I'd consider myself and only myself bad and know I have more work to do. If I've tried my best to help and it doesn't work, then at least I tried. Hopefully it sticks somewhere and whoever it is doesn't run into major issues down the line.
I have to be careful, to an extent, at how I approach this sort of question. I see many sides of an argument. I am a slow learner (my brain is borked!), and have anxiety to boot, so I'm very conscious of the fact I really have to double down on my efforts everywhere to have success. It can be very tiring, which is why you're unlikely to see me doing some of that more difficult content (savage stuff. That kind of thing). I can't deal with many rinse repeats in one hour for example, it's too overwhelming and draining physically and emotionally (I will try another time if it's really important to me, however).
Still, we lead by example. If we don't do the best we can do, be that using all our toolkit at the appropriate moments or simply just making sure the party sticks together and looks after itself, adjusting expectations based on who is in the party, all whilst keeping a healthy line of communication open, then we're probably all bad players. I'll also say I personally like to swot up as best I can ahead of going into something, particularly if I've not done it before, or have only done it once or twice, but I do that to compensate for the fact I don't always pick visual cues up so easily, and if there are patterns and/or lights, I can't guarantee I won't get caught short. Forewarned is forearmed for me in this case.
We can have ranting, venting threads because mostly it's good for the soul so things don't fester and build up into resentment (frankly, I see Tales from the DF as a confessional of sorts). We want others to give us a little support, even validation for our decisions, instruction on what to do if it happens again, and forgiveness if we did eff up (own your mistakes, everyone, and enrich your lives).
We've got people from round the globe, all walks of life, ages, etc., playing this game. We've got people with still developing reasoning skills, people who don't fully understand themselves let alone anyone else, people with different physical capabilities, mental capabilities, different belief systems, customs, cultures. We're going to run into differences of opinion on anything you can think of. Any thread on the forum, this one included, demonstrates this. But here's where I hope we can at least try to agree: being courteous and understanding with each other is a great start ahead of improving anyone's respective gaming skills. I can't help but think it starts by not calling people "bad" for missing that, and having forgiveness for ourselves and others when mistakes happen.