Nobody in this series should think tapping someone to pass them is legit regardless of how light the tap is or how much faster they are. That is 100% dirty. I hope when you say "a lot of drivers" you aren't referring to anyone in this group. If you know of someone who has or does use that tactic bring it to our attention and it will be dealt with swiftly.
In the many races (approaching 100) I've run in this series nobody has ever intentionally tapped me to make a pass. I've been punted completely off track a few times, but never on purpose and the driver has always waited for me so gained no advantage. The OLR requires a concession like that for the offending driver specifically to prevent that type of tactic.
All of us make braking mistakes from time to time, especially when we are in a tight pack. I know for a fact that I tapped a car in front once or twice yesterday between the two races (EU and NA) and I was lightly tapped a few times myself. But none of these incidents ended up with anyone spinning or off track and in no case was an advantage gained. Well, I ended up off track rather than completely punt Hydro when I missed a braking point, but you get what I mean.
Just don't take advantage of that kind of mistake and don't make it a pattern and you'll be fine. I don't think there is a single driver in this group that has never accidentally tapped someone, even the aliens, so don't be hard on yourself either.