Don't forget that LCDs only have one resolution and if you can't match that one, it will interpolate so it fits, which makes it look blurry. Just try running windows in 640x480 on it and it will also look very blurry.
Also they sample the analogue signal, which a regular analogue monitor doesn't have to, which amplifies all distortions by several grades.
Btw, see if there are any noise-filters or anything image-enhancing crap which you can turn of for the scart-input. Atleast LCD TVs atleast are filled with that kind of stuff, which degrades GUI stuff.
There can be issues with your cabling too - often the el cheapo Amiga RGB cables doesn't have coaxial cabling for the red, green, blue and sync signals.
Also, they often for some idiotic reason have resistors connected in series with the red, green, blue and sync signals which is completely wrong - this will in combination with the 75Ohm termination resistors in the TV/Monitor/etc create a voltage divider and make the picture dark compared to other sources as the signals from the Amiga isn't 0.7Vpp anymore.
If you have to turn up the contrast on your TV/Monitor/etc when using the Amiga to match the other sources, you have these resistors.
/Patrik