Treza you clearly have no idea what you are talking about, Scrolls can only be used to TP to buildings so the idea that you can gank with them is just wrong. It's obviously different from TF and Shen's ult.
Saying it is no risk is also wrong as well, you can die wherever you are on the map. If for example a tower is being pushed and you TP in to defend you run the risk of dying, you also leave your lane so you have reduced farm and xp.
What you guys seem to think TP scrolls are are Boots of Travel in DotA, which are boots with high MS that give you the ability to TP to any friendly unit. However they cost 500 for the Boots and 2200 for the Recipe. That's a lot of gold for boots so essentially only Tinker buys them because of his Rearm TP combo.
Do some research before you make your irrelevant comments.