Rocky, sorry to hear you had a bad day. I've had good and bad days there myself. You're right that the birds are mostly common, though we have seen a few relatively rare birds like the Bittern.
i wouldn't say it was a "bad day"... no day spent outdoors with my camera is a bad day!
it just wasn't one of my most productive outings. but i still enjoyed myself, and my daughter had a good time as well, so it was worth the drive.
If you have a place nearby that offers the same birds, then you probably don't have any reason to go there. I like Nisqually, since while I have the same birds around here, including many literally in my back yard, they're easier to find at Nisqually, and the background tends to be photogenic, rather than suburbia.
that's what i like about Juanita Bay Park... it's big enough that the neighbor's house isn't in the background (though you can sometimes get houses on the far shore in the picture), but there seem to be at least as many species, and you can get a lot closer to the birds. i've shot GBH's, green herons, bitterns, swallows, blackbirds, wood ducks, snipes, rails, hooded mergansers, muskrats, hummingbirds, and otters all from less than 25 feet away. and of course, there are eagles, hawks, and a number of other species of waterfowl as well. sure, you won't see all those every trip - sometimes you won't see any, or maybe only one, but you'll get a good shot when you do.
while i was down there, i overheard a group of birders chattering and pointing, so i wandered over to see what the fuss was. they were all excited about seeing a Bewick's Wren in a thicket 50 feet away. i didn't have the heart to tell them that i've gotten shots of those little guys from 10 feet away, posing for me in the open, at Juanita...
in fact, here's one now...