What you definitely want to do is trim down the channel list. Go to Menu > Favs/Setup/Parental >Favorites, and set up Custom 1. Add "What I Get", then start deleting from there. Trim out all the junk that doesn't interest you and it'll feel a lot better while browsing.
There is no real rhyme or reason to any provider's lineup (although Dish's is the worst because they have like 5 copies of each channel scattered all over the guide), but I wouldn't doubt if the networks pay for placement in the lineup where they think will get them the most viewers. The home shopping and infomercial channels are everywhere because they pay for multiple channel slots. Same with the 'game lounge' channels. Basically 100's are PPV, 200 and 300's are 'the usuals' or 'expanded basic', 400's are international, 500's are movies, 600's are RSNs (regional sports networks), 700's are sports packages, 800's are music, 900's are system info and private networks, 1000's are On Demand.