Why is isopropyl alcohol a good solvent?
Need to be slightly cautious with terms like "Good solvent"...............
I think you need to be slightly cautious with descriptions such as "good solvent" - it really depends on what you need to it to dissolve - water is a pretty good solvent if you're trying to dissolve ionic compounds. Its not so great if you want to dissolve oil!
However, in general terms IPA is often used because it has the ability to dissolve a wide range of non-polar substances, it is relatively safe to use, it evaporates quite easily under normal lab conditions (boiling point is not that much higher than that of ethanol), and it also has two major advantages of its close relatives: (1) it is less dangerous and/or toxic than methanol or n-propyl alcohol, (2) unlike ethanol, it does not require denaturing.
Denaturing is done to ethanol to make it undrinkable - the denaturing additives can cause a small oily residue - with IPA you don't get this.