It was. It was really good. And that's why it got nerfed. You provide a great example yourself "It allowed a nice escape if timed right when ganked that even flash could not get you because of the short duration." outperforming Flash in the same use but at half of Flash's cooldown. You only bring up escaping ganks, but the spell has more use beyond that. It can be used to escape, but it also be used to gap close and people in high elo were taking it as a combat choice as well. Ghost was serving as Summoner Spell that worked in multiple use cases without the limitations of use of something like Ignite.
"You wouldn't have a warmup on flash would you?"
Well, of course not. There are two benefits of Flash, that it works instantly and that it increases ability to reposition. You can only reposition in that moment, but even so that is strong in League that it is the reason why it has the history of nerfs that it has. Ghost gave an immediate benefit, it increases ability to repostion and and increases it for 10 seconds and on top of that, for half the cooldown.
If a champion requires an instant "Oh $%&!" button that gets them to safety, then shouldn't they pay for the cost of that benefit with 
? And if they don't require that, shouldn't they then enjoy the benefits of 
as well as its greater uptime?
