A big part of it is the time of year, there aren't many feeding windows for a bank beater to take advantage of in the heat of summer, this will change as the season transitions and things start to cool down. Also possible is that you've had bites and just missed the signs, they don't always hammer a presentation, often times the only indication you get is your line/lure doing something it just shouldn't do like stopping too early, moving to one side or the other slightly, and they spit it back out before you start your retrieve. Fishing summer and winter from the bank are a real challenge, because the fish aren't going to cooperate and hang out where we can get to them very often, but you'll get one, just stick with it. Those senko's are a good choice, one thing I find helpful over the summer since I haven't got any electronics is dragging a Carolina rig around and mentally napping the areas I think ought to be good fishing, figure out where the hard bottom bits are, where does the grass line start/stop, is there sunken cover or brush piles I can't see that might be worth remembering? If I catch a fish it's just an added bonus, and often times finding a grass line or something will catch a fish, but when the fall or spring rolls back around and the fish start pushing shallow again, you'll have a lot of dead water already eliminated and can focus on higher percentage areas.