If we are going for lines, I don't see any reason for a category under 100 lines. Even on level 0 start there are over 200 people on the board with times under 10 minutes so it's not a lengthy speedrun.

It would be great to get more people involved in Tetris but removing the need for a level of skill isn't the way to do it. Learning how to get to 100 lines really isn't that difficult.