Normal for a 1000$ tablet pc? You seem to have an excuse for every issue

this is absolutely not normal and totally annoying
My laptop cost 2000$ and the audio is total crap, like all other laptops and desktops. Not a single review mentioned how crappy the audio was (Dell Latitude E6400, check it out), yet the audio is crap. Oh and forgot to mention, when the system is plugged in, you hear internal interference like crazy. And no it's not a faulty motherboard, I already exchanged the system 2 times when I got it, and the system board was replaced 1 year and half later under warranty, due to a wireless card (issue with a specific revision of the Intel wireless N card with university routers) replacement which gone wrong by the technician that came over (he drop a screw inside, could not get it out, without pulling the heatsink out, since i had overheating problems as the thermal paste was not replaced when he put the heatsink back after getting the screw. Dell decided to to send me a new (confirmed with the manufacture date sticker) system board and heatsink), and the sound was still the same crap through any headphones.
Money isn't invested in sound quality, because as you can see from the manufactures of sound card, it's a niche market. People don't care about sound quality.
You have 2 companies at the consumer level: Creative Labs that is barely surviving, and cant' afford developers for half decent drivers, and then you have ASUS which makes great product and good drivers, where their audio department is not making any profit, nothing significant at least, but do it because they want to, for the gamer that cares, and audio enthusiasts.
If you want manufactures to change this, then you need to demand it. Meaning: Start buying dedicated sound card, show to manufacture that there is actually a market for quality sound, and that people care, and then you'll get them, to put a higher grade sound solution and better components to output, as a result, better sound. It must be noted as well, that, and this is something I forgot to mentioned, is that those cheap-*** onboard sound card have 1 big strength over a proper sound solution: significant reduction of power usage.
My dedicated sound card, for example, requires, much like my graphic card, a dedicated power to power the card for additional power, and it is true that using a USB sound card will draw more power and visibly reduce the system battery life.