They had exactly the same effects then as they do now. That if you are attempting to do a key on time or push it that you want capable people. It is always a risk taking on strangers in pugs but you can reduce the risks when you can see what experience they have.
Anyone can push their score if they want to. You do not have to be a ‘no-lifer’. There is no requirement to buy boosts. You can push your own keys with any group of people you see fit, you can do them with friends, guildies, communities or random strangers. If you want to take the first Tom, Dick and Harry that apply regardless of their experience then you can do that.
People seem to feel they have a right to be invited to every key that they apply to. It’s the person running the group who has the right to invite whoever they deem fit. You are not the only person applying to that group, most will wait and see what selection of applicants are available and choose from the list accordingly. Sometimes you get declined because your score is too high and they think you will just leave if the key isn’t going to get timed or there are mistakes.
Time spent in game is not equal to their skill level either. As Deja tried to explain previously there are people in the same gear as us doing far higher keys. I wouldn’t expect any +20 group to take me when I have so little experience or success rate in them. However any +15 I apply to is pretty much insta accept. The addon shows them my score and that I’ve completed around 99 +15s on time. I’m a pretty safe bet to take to a group. I don’t care about timing it either because I don’t need any score for that dungeon. I already have it.