It depends on genre.
In country the lyrics matter because country lyrics make heavy use of puns and wordplay. If you write abstract country songs you will be doing so in your basement and no where else with your dog as your only fan.
Adult alternative or grunge influenced uses more esoteric lyrics that are open to interpretation. If you write alternative music don't use lines like "she broke the only heart I had left".
If you are writing Rap or R&B lyrics nothing else matters except using "dayummm", "ooohhhh", "baby", and learning the various street slang terms for: money, male and female gentalia, sexual positions, the names of various expensive luxury goods, drug names, and firearms.
In any "metal" genre just write any damned thing down and kick it at 640BPM. It doesn't even have to be intelligible.
Americana/roots/folk need story songs, abstract songs, and personal confessional songs. Throw in some political/activist stuff. In this genre it is absolutely paramount that you write music with a meaning and that means lyrics with a meaning or you'll be sitting next to the abstract country writer playing for his dog. People listen CLOSELY to the lyrics here.
Jazz/Blues/Rock-n-Roll - easy the music takes the forefront no matter what until you start talking about acoustic delta blues where the lyrics and not the fretwork come back into play.
I don't think that you could convince Paul Simon, Damien Rice, Bruce Springsteen, Tori Amos, Tracy Chapman, Townes Van Zandt, Johnny Cash, Lori McKenna, Gillian Welch, Ryan Adams, Bob Dylan, Lucinda Williams, or John Gorka that lyrics don't mean anything.
They didn't get what I was meaning, till I stopped meaning too much
-John Gorka "Thoughtless Behavior", Out of the Valley (1994)