[taylodl]

Because you can see the tuning of all the strings at once. You strum and they all show up. Then you can see which ones are more out of tune than others and tune them together. Prevents problems where changing the tuning (tension) of one string throws another string out of tune. I call it "global tuning." It gives you precise tuning extremely fast.

[someweirdperson]

Does the tuning of one string affect the others on guitars with hard tails, or is this mostly a tremolo induced issue?

[pravus]

Yes, for hard-tails. Neck construction doesn't matter either. I notice it on both bolt-on and neck-through instruments. My method is to tune the highest strings first and work down to the lowest since that seems to minimize this effect.

[themarkn]

I believe the issue is due to small changes in the overall tension on the instrument caused by changing one string’s tension.

[RHSman2]

Ok. Sold!!! That is awesome.