I suggest you download and try the media players i mentioned then you would have room to talk.
I'm not an expert or a software developer, so cannot provide an explanation as to why some media players sound better than others,
they just do.
I don't agree with you simple bits are bits explanation.
It may depend on how transparent your audio system is.
1. You are right, software sounds different. However
2. I find it very disturbing that you liked Nero most. I mean... No, I don't meant anything at all. Nothing to see here. You must wither really like it's particular sound, or have a setup which reacts better to it than to other software.
You might want to check your settings. Bits ARE bits. If you think you are hearing things that sound better you might want to check the EQ in those programs. Windows media player doesnt even bypass the windows resampler.
Thats the bad thing about subjective things like "this sounds better" people always forget the "for me" part.
At first I was going to argue over the fact that Nero cannot be the best software for music playback, there is foobar, fidelizer stuff, jriver, etc. but then this statement came up.
Bits are bits. Data. This data is taken in samples. One second is split in 44100 points of data, in which data is measured in 16 bits, think of them as +8 to -8, where positive and negative are relative to a zero in which the driver is in resting position. These points need to be interpolated, using quite complicated algorithms, high pass, low pass, filters, then OS will resample the music, then OS kernel will add it's own flavor to the music.
Nothing can bypass this to this day, only players with dedicated OS are immune to this.
Now, I can assure you want winamp does not sound like foobar, and if you download and test, you will hear obvious differences. It is not relevant which sounds better for you, but that they are different.
All software sounds different.
My own project will have it's own sound, it is inevitable. The most important aspect is which sound closest to real, natural music, and if that one is the best for all people. (HQplayer is a king is sound quality, but using it....... I simply given up after having to stop song each time I wanted to change song or modify a setting.)