When git gc does exactly the opposite of what you expect

gistfile1.txt

user@PENSIVE ~ $ du -sh *-web/.git/objects
42M     2-paystream-web/.git/objects
57M     3-paystream-web/.git/objects
73M     4-paystream-web/.git/objects
8.1M    paystream-web/.git/objects
user@PENSIVE ~ $ for i in *web; do pushd $i; git gc; popd; done
~/2-paystream-web ~
Counting objects: 171965, done.
Delta compression using up to 8 threads.
Compressing objects: 100% (33235/33235), done.
Writing objects: 100% (171965/171965), done.
Total 171965 (delta 135697), reused 171965 (delta 135697)
~
~/3-paystream-web ~
Counting objects: 177396, done.
Delta compression using up to 8 threads.
Compressing objects: 100% (36006/36006), done.
Writing objects: 100% (177396/177396), done.
Total 177396 (delta 140173), reused 175361 (delta 138288)
Removing duplicate objects: 100% (256/256), done.
~
~/4-paystream-web ~
Counting objects: 175014, done.
Delta compression using up to 8 threads.
Compressing objects: 100% (37131/37131), done.
Writing objects: 100% (175014/175014), done.
Total 175014 (delta 138198), reused 171489 (delta 134814)
Removing duplicate objects: 100% (256/256), done.
Checking connectivity: 186721, done.
~
~/paystream-web ~
Counting objects: 174716, done.
Delta compression using up to 8 threads.
Compressing objects: 100% (37602/37602), done.
Writing objects: 100% (174716/174716), done.
Total 174716 (delta 137934), reused 170522 (delta 134050)
Removing duplicate objects: 100% (256/256), done.
Checking connectivity: 185755, done.
~
user@PENSIVE ~ $ du -sh *-web/.git/objects
42M     2-paystream-web/.git/objects
43M     3-paystream-web/.git/objects
76M     4-paystream-web/.git/objects
75M     paystream-web/.git/objects
user@PENSIVE ~ $