I'm curious how many people in the real world actually use IRC. Find 10 people on the streets of New York and statistically zero use IRC and maybe, maybe 1 has even heard of it. Ask those same 10 people if they've heard of WhatsApp and likely 3 or 4 would have heard of it and probably 2 would have it on their device. If they're from outside the US, that number would go up to likely 7 would have it installed. Ask those same 10 people if they've ever heard of Skype and all 10 would say yes and likely 8 of them have used it.
Obviously this isn't scientific, but the point is that most people don't use IRC. I'm a software dev and I don't use IRC and I've never had a real-world non-dev even mention it. But Skype? I'm forced to use that every day. Text messages? With iMessage, it's great, but you also need to have the person's phone number -- or, you're like me and you're moving around a lot and change numbers fairly frequently, but Skype/iMessage/etc stays pretty consistent year after year.
Just my 2 cents. In terms of "always on intrusiveness" isn't SMS always on? Unless you're using a burner phone, you're being tracked, SMS is always logged, there's no illusion of security.
Besides, who the heck buys a phone is Hangouts imbedded in ROM? If you're interested in security, then I'd suggest getting something other than Android.