Because the green/blue/black designation only applies within a resort i.e. to compare trails at the same resort to one another. It is entirely useless for comparing a trail at resort X to a trail at resort Y. What rates green at one ski area can be black at another, and vice versa.
So, I gave up on looking at those stats a long time ago - it's completely useless information.
Good advice from others upthread. Not to pile on, but avoid Snowbird - the green trails are all unpleasant cat-tracks, and the blues would be rated black at most other resorts. Plus, you can easily take a wrong turn and find yourself way over your head - at most resorts you have to work to get to the real gnarly stuff, at Snowbird it's right there.
Brighton has the most easy cruisers, so I'd argue for it. PCMR is another good choice - lots of blue cruisers and high speed lifts to move you around the mountain. There's certainly more nightlife in PC, but both lift tickets and lodging are significantly cheaper at Brighton, especially if you stay in town (Sandy, Midvale, Cottonwood Heights) and drive up each day.
If you like skiing flat cat-tracks through real estate developments, the Crayons is your place. Otherwise it's pretty much a real-estate development in search of a ski resort and imminently skippable.
Solitude is known for truth-in-advertising - it's rarely crowded. But the blues at Solitude are generally steeper than anywhere in SLC except Snowbird, so it may not be your best choice. You'll certainly find some terrain you like, but you may find that the top-to-bottom trails are a bit challenging. Perhaps go there on Saturday to avoid the crowds elsewhere.
Nobody has mentioned Snowbasin yet; I'd say put that on your short list. There's lot's of area and several easy ways down from the top (and more challenging ways too). There's no lodging at Snowbasin, so you'll be commuting.
You don't say how long you're going for, but if you're going to be there for more than a few days I'd say sample a couple of resorts and then go back to the ones you like. Brighton, PCMR, Snowbasin would be my short list based on what you've said about yourself. If you stay in Cottonwood Heights, it's about ~20 minutes to Brighton, ~30 minutes to PCMR and ~50 minutes to Snowbasin, depending on traffic and weather, of course.