One way to make the Hextech GLP-800 more attractive

Instead of stop movement completely when using it, why can't you use it while moving? Or at least have a brief slow instead? It feels awkward and bad to have to completely stop to slow the enemies. It just feels more like a support item.

The only champ I see buying it is . Literally the only champ.

You could of course also reduce the damage or slow by a Little for compensation, but it's worth it.