Hi Mireille! - My take is that the "These Days" singles weren't huge hits like many of their others and as they have such a huge catalogue of hits to choose from now which gets bigger with each album, it's hard to fit them all in the set! However, Jon does still put "Something to Beleive in" and "These Days" in the setlist occasionally and has been known to add "Hey God" once in a while too!

Hope this helps.