From what I remember, Unskilled player's purpose is essentially flagging someone as being in an Elo that's to high for them. The Rioter explaining it seemed to indicate it's actually the report they act on the most as well.
It's intent isn't to punish players with a bad attitude, abusive behavior, or ones that intentionally feed.
It's more to re-set someone's Elo when they're in over their head and just can't keep up with everyone else. Maybe they came back after 6 months of not playing, maybe they kept playing in 5-man pre-mades and got carried hard 1 to many times.
All things considered it's kind of a win-win if you get reported for it and things happen. If you are skilled you should be easily able to carry yourself back, if you aren't - you'll probably have more fun against players at your level.
If you're doing pretty average in your matches I doubt you'd have your Elo re-adjusted.