With Lily Lake right on the highway, a large parking lot, a handicap-accessible loop trail, and every piece of park literature touting it as full of greenbacks -- guess what? But, one of the most exciting fishing experiences I've ever had was in a canoe on Lily Lake one evening with a massive spinner fall going on -- surrounded by cruising, slurping cutthroats. You'd try to figure out the fish's trajectory, and lay a fly in it's path. I'm sure I didn't have the place to myself, but I don't recall anybody else being out there. And it certainly wasn't fishing in a parking lot.
To each his own, I guess. I've found that being willing to get up a little earlier, stay out a little later or walk a little farther will help you avoid folks.