I used to be critical of the wave when the home team is batting, still a little critical when it's a close game (not sure 3 runs in the 9th counts). But with a 3 year old, it is another thing to interest her and extend her time at the ballpark. I support it. Also, unlike a lot of other annoying things at sporting events, you can't really replicate the wave anywhere else. It's a whole ton of people, sitting captive, in a circle formation. If that crowd wants to take some communal action for fun, go for it. For those that don't participate, its direct effects (blocking one's view) are very brief by definition, and given the pace of the sport, unlikely to obscure much action.