Hmm"let's put this in allegorical terms. Say Barack and Dubya we're cruisin' in Dub's bitchn'-new-midnight-blue Z28. It's late, and both presidents may have had a few highballs (Dubya's also chattering and sniffling, but who knows what that means?).
Anyway"they're chit-chatting. Dubya has got Obama just rolling in his chair with his wild tales about "hidden WMD" and "Hanging Chads", and is generally not paying attention. Suddenly, a sharp curve approaches. There is no question that Dub should've seen it sooner and been prepared, but he wasn't. As the car plows through the guard rail and careens over the cliff, Dubya tosses Barack the keys and screams "Amuricah sez "Take the Wheel!"
Bush Parachutes to safety, never to be heard from again (or until his 2010 Book-signing tour). Obama, heroically slides over to the driver's seat, steels his resolve and braces for impact. In a display of masterful skill he lands the car on all four wheels and then miraculously is able to limp it to a nearby gas station.
When he arrives, he is surpised to see John Boehner, Sarah Palin, Rush Limbaugh, Anne Coulter, and Michele Bachman eating doughnuts and sippin' on sweet tea.
"And what have you done with Georgie?!?"
"Police!!!!!!!!!!!!!!"
Back to the question posed in the post's title: "Progressives often still mention Bush, because between 2000 and 2006 The Republicans controlled the White House as well as both branches of Congress; and they went BUCK WILD with the power and the back-scratching and the spending and the war-mongering; and that is a very large part of why we are where we are today.
In conclusion, Bush and his Congress' are still relevant to todays crises, and thinking people like to deal with all the relevant information.