I've never been on any of the four rides that make up A Bug's Land in Disney California Adventure Park. I'm a little too old for them. The Bug's Land target audience is the age 3, 4, 5 demographic (and their parents of course). Because the target age is so limited, people are forever wanting Disney to remove A Bug's Land and "put in something better." Not so fast. When people say "put in something better" they usually mean "put in something I might like, something I can go on." Their interests are sometimes pretty self serving.
Now granted, the Bug's Land rides are basic off the shelf carnival rides that true Disney people seem to loathe. They want everything "imagineered" and built from scratch. Sounds expensive to me. When DCA first threw open its doors. one the (many) complaints was there was very little in the park for little kids to do. Almost immediately, Disney constructed A Bug's Land as a companion to the It's Tough To Be A Bug 3D show (which terrifies many small children interestingly enough).
The little rides of A Bug's Land serve their purpose and graciously entertain their little guests. What small child wouldn't want to take a spin in a box of animal crackers or a box of Chinese take-out, or spin around in a lady bug, or drive a bumper car, or take a ride on a caterpillar train that has a funny voice? A Bug's Land is fine, leave it alone.
I always like to pass through because I find it charming and it has such a small footprint in the park. I enjoy it better than ToonTown in Disneyland because it actually delivers rides instead of stylized facades. The space in A Bug's Land is not wasted, it's put to use with wonderful whimsy. And at Christmas, Disney adds to the charm of the area with some wonderful decorations. So give the 3 year old his space. If you are A Bug's Land hater remember that the Disney parks aren't exclusively about YOU. Sometimes sharing the fun is part of the joy.