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).