What's wrong with the name? "WhatsApp" sounds pretty dumb to me, too, but it's entrenched in the social consciousness, so we don't really think about it.
(The name even has nothing to do with chat; originally WhatsApp was a way to share your "current status"; "WhatsApp" sounds like "what's up?".)
Birdy evokes the same energy as "BabySeal". I imagine you can understand why an app called "BabySealChat" would be off-putting to a thirty-something disgruntled developer?
I don't think Whatsapp sounds dumb. It's "what's up", and it came out when mobile apps were getting popular with everyone. I immediately got it when I heard it the first time, and it sounded good to me.
"BirdyChat" just sounds childish.
Maybe I'm in the minority, who knows, but project names are important. I've seen so many posts of people dismissing projects just because of the name...
Complaining about names seems like a surefire way to induce endless bikeshedding conversations that go nowhere. It's also often cited as a too-convenient excuse for why a service fails that doesn't really account for the market realities or whatever systemic failures were at play.
The truth is that 15 years ago, "tweet" was seen as a joke by those who weren't extremely online. It didn't stop Twitter from becoming a desirable place to socialize, at least for a time. If the internet made "tweet" happen, people can get used to any weird nomenclature.