To be honest, I really love my rMBP 2014 hardware, it was basically perfect. Great speaker, as you say, good enough keyboard, BEST display, etc.
If Apple releases another MBP based on 2015 I'll take a quite good look again.
Of course it would be nicer if the laptop had better speakers in it, but there are always trade-offs to be made on cost vs benefit, and fairly cheap bluetooth speakers are a pretty good workaround for a lot of people.
What I'm trying to say is that if really good audio quality is important to you, then having a couple of sets of bluetooth speakers in your house strategically placed in the places where you'd regularly watch movies or consume other high-quality audio is a reasonable workaround for a lot of people. OF COURSE having better speakers (equivalent in sound quality to the bluetooth workaround) in your laptop would be better if you care a lot about audio quality. But that would add to the cost of the laptop for every user, even the ones that don't care about having really high-quality audio on their laptop. I'm saying that it's not unreasonable for a manufacturer to make some tradeoffs like that when there are workarounds that work fairly well.
Over time the costs of adding higher-end features like this drop, and things like audio quality improve to the point that the workarounds aren't needed (the audio quality of my phone speaker is actually pretty amazing).