I disagree... It's exactly what we should be doing.
Yes, transport is not exactly there but you're talking about an event which is aimed at the 18-30 crowd. It's not a conference for old codgers. Everyone will find their way there with no issues I'm sure
Manchester, albeit with a better transport link had a concert at the coop arena and a match at the Etihad the same evening... That's 55k and 22k venues right next to each other. This is on top of an event at the arena plus a few other venues in the centre, all on the same day.
If Liverpool wants to be considered a top destination then multiple events all going on is a good thing.