The reason to supply a reference should be obvious: you are the only one who knows the reference that supports your suggested edit.

There are numerous possible references out there, and if the first one we check does not support your edit, then we have to keep checking through references until we find one that does.

It is a matter of simple courtesy, and not an onerous burden.  If you're taking time to submit a change, then take the slight additional time to supply rationale or a reference.

@@ -25 +25 @@
-<gloss>appear</gloss>
+<gloss>appeal</gloss>

gg5, prog, daij

The references box is there for a reason. I don't know why you're complaining.
We're not asking a lot from you.

@@ -24,0 +25 @@
+<gloss>appear</gloss>
@@ -26 +27 @@
-<gloss>thing that separates something from the rest</gloss>
+<gloss>attractiveness</gloss>
@@ -30,0 +32 @@
+<gloss>taste (e.g. of victory)</gloss>

daijisen daijirin

You have plenty of sources at your hand. Isn't your "job" (I get it's a volunteer thing but still) as an editor to check edits against 
those? Even if I provided a reference, you would still have to double check it, so I don't think it's the case that I'm creating a whole lot 
of work for you.

@@ -26 +26 @@
-<gloss>thing that separates one from the rest</gloss>
+<gloss>thing that separates something from the rest</gloss>

Please provide some.

@@ -25 +25,2 @@
-<gloss>style</gloss>
+<gloss>uniqueness</gloss>
+<gloss>thing that separates one from the rest</gloss>