Why does a PS2/S-Video/TV picture look SO much better than a PS2/S-Video/TV Tuner card/Monitor?

[MCS]

Both using S-Video, I have a good 19" monitor too. But it looks pretty inferior. A lot darker and more blurry, I have to deinterlace too. Is there a specific reason why it looks so much worse or am I doing something wrong?

Using a Hauppauge WinTV PCI card.