correct me if im wrong, but as far as i know, people who think like that dont have much to do in these forums.
As much as people who plug expensive headphones into the onboard analog output on a desktop computer's motherboard.
Look, it honestly doesn't matter to me what you do. Do what you please and enjoy your music. But I want to tell you one basic fact I discovered when I bought my first decent headphones and tried to connect them straight into my computer:
The integrated audio systems on computers suck. They've improved in the last few years, but they are dreadful - truly, truly dreadful. Honestly. If they were sound cards, they'd sell them for $2 in Maplin in the bargain bins. They totally lack power as 'amps' (plug something higher impedance into them and you literally don't get any bass frequencies) and they get a LOT of interference. On good headphones you can actually hear little clicks and whines as various components power on or transfer data. I'm told it's EM interference (don't quote me on this, I'm not an engineer) and that it's because the DAC process is taking place inside the computer - this is why high-end sound cards often have EM shields and special circuitry to filter noise from other components, and why motherboards often have TOSLINK outputs so you can feed the digital signal into an external DAC and amp of your own choosing (this is what I ended up doing).
Basically, if you care about audio quality at all, a motherboard's 3.5mm analog out is just about the worst thing you could possibly use, and worrying about Blu-Ray audio while using one is deeply paradoxical - like agonizing over your choice of bodykit when you're driving a Ford Kaa.
Before spending money on the 'bodykit' (Blu-Ray audio) you should really do something about the 'Ford Kaa' (the audio system). Consider getting an external sound card like the Creative Omni or a USB headphone amp/DAC combo like the FiiO E10k - these devices connect via USB and get the analog conversion process safely away from the cage of EM interference that is your computer, as well as providing a MUCH more powerful amp than your computer's integrated audio chip, which was designed more or less exclusively for speaker systems with their own amps (insofar as it was designed to do anything beyond making the Windows chimes audible). If you want to be fancier or have more options in the future, get a separate DAC (like a FiiO Taishan or one of those cheap USB-to-analog dongle soundcards) and a dedicated headphone amp like a Schiit Magni 3 or an Objective2 (if they're still around). Those are the two I'm vaguely familiar with (I have an O2) but Amazon has loads of other options as well, to suit all price points.
Covering these two bases - DAC outside the case, and a decent amp - with separate amp and DAC, or a DAC/amp combo, or a USB soundcard that does both - will transform the sound qualty you're getting. That should be priorities #1-100. Blu-Ray audio should be priority #101.
This all assumes you're still going to use the computer at all. If your existing hifi setup is decent, it'd make a lot more sense to just add a home blu-ray player to that. Most blu-ray players have TOSLINK out.