You can get those echo-y effects from autotune pretty easily. I definitely heard a shit ton of autotune in his vocals when i listened to it. You could hear his voice warping in and out of tune constantly throughout the song, sometimes in the middle of a word. That's one of the key signs of someone using autotune.
The thing about autotune is that is doesn't cure someone who can't carry a tune, which Tom can't do without studio trickery (see Blink's live album for examples). All it does is mask it or makes it stick out like an even larger sore thumb. That's why the autotune sticks out because you can hear it reaching to correct his voice but it doesn't work. This is what usually accounts for the robotic-type sound you get in a lot of rapper's voices. If you have someone that can hit the note without autotune, you don't notice it in the song.
I can't speak for anyone here, but it's not that I hate vocal effects by themselves. Lots of songs use modified vocals to create a cool sound that fits the atmosphere that the song is trying to create. The newest Sufjan Stevens album has a few really good examples of this. But Tom, as seen with AVA, uses autotune and other studio effects in the context of otherwise generic modern day emo music in attempt to make it sound more atmospheric than it really is. If you take this song without all of the studio effects it's incredibly bland.
As far as the maturity thing...it's not that anyone expects 40 year olds to be singing about what it's like to be stood up for prom, or fucking a dog in the ass. But at the same time Tom's obsession with making "PROFOUND STATEMENTS" that are essentially just really shitty meaningless phrases is what kills it. There's ways to make mature music without saying things that are that stupid. There's also ways to make immature music without sounding like children. The band has plenty of options that could be better than the route that they're going in. The big issue seems to be that the band, like a lot of mainstream rock bands these days, thinks that maturity has to be tied to BIG PROFOUND STATEMENTS and epic sounding music when it doesn't need to be. Lots of pretty simple punk bands (The Thermals, Ted Leo, etc) have done an excellent job at transitioning from bratty pop-punk to more mature music without ripping off U2 or Bad Astronaut or constantly making asses out of themselves like Blink does.
And I want to say real quickly that I do think these dudes have it in them to make a good album. A few songs on the self-titled album have some good ideas under the overproduction, and they've proven that they can write catchy music when they want to.
"I'll die before I surrender, Tim".