You speak truth. The three dogs were at least a novel idea at the time, but four generations in a row with legendary hunting is a bit wearisome. (I'm also not sure why I can't find Tornadus on my White file... I'm sure the answer's in 100 places online, but I'm loathe to start searching for it, since that feels a little cheap to me in most cases.)
I mean, I get that legendaries are supposed to be hard to catch, and so in some sense I appreciate the hunt. But on another level, I'd at least prefer that they fight back for a few moves before fleeing, if only because it would feel more like you were making progress. That would also allow you to see the actual power of the legendary (as opposed to just its ability to run away). It might make the capture a little easier, but I think you could compensate for that by upping the level of the roaming legendaries. Make them level 60 or something, but have them actually use 0-3 or 1-3 moves (which could be randomly determined) before taking their leave.