I use Lightroom, and make liberal use of the x key. Shooting with a 7D also often means I have 5 or more photos in a string from one long burst. If it is a really interesting bit of action then I will sometimes gather the photos and make a gif, or post them as a single set together. If the continuity of the photos isn't important then I will step back and look at the series to identify a single photo that best captures the entire burst of images.
If I'm simply not happy with any of the photos from the burst, then I'm not at all worried about flagging them all as rejects and moving on to the next burst of images. I still make bad choices, shooting too wide, or deciding that the player positions and framing just really don't work the way I had hoped when I can view them on a full sized monitor.
There is nothing wrong with deleting images, especially digital, if you are not happy with them. Be hard on yourself, think as you process, and decide what works for you, what doesn't, and most importantly WHY something isn't working, especially if you're doing a lot of it.
And this reminds me, I have about 1800 images from last Sunday that I still need to sort and post. If I don't, then the derby girls may lynch me.
That's precisely why I don't delete anything. Once I hit the delete key, that's it. I can't decide why it isn't working, because now it's gone.