I don't think I'll ever take T20 seriously but that's largely because it doesn't itself seriously. Cheerleaders, fireworks, pop music etc.
I can still get invested in it as a game. Of course it's not as complex or intriguing as Tests, but then you have to remember that we're all really weird for liking Test cricket, which is about as spectator-unfriendly as mainstream sport gets. T20 is a form of the game that's closer to the norm, but it's still a lot more complex than say, tennis, or darts, or games of WordFeud (at least one of which I tend to get extremely worked up about).