Not that the Enterprise was a total waste. They're a thrifty bunch over at Cape Canaveral, so when it became clear that their first space shuttle wasn't going to be up to snuff - after spending somewhere in the region of $196 billion on building it (for comparison, that's about how much Donald Trump spends on a light brunch) - they decided not to simply junk it, or have it exist as an exhibit in a museum or something. No, they stripped that sucker for parts they could use in a shuttle that would actually fly. Refitting the Enterprise for spaceflight, after they realised the flaws in the original design and changed them, would have meant totally dismantling the orbiter and returning the component parts to subcontractors across the country with built them in the first place. And they did consider refitting it after the Challenger disaster, but still it seemed too costly. So instead they took the thing apart, kept the important structural bits and chucked the rest away, and that's how they cobbled together the much more successful Space Shuttle Endeavour, which was a sort of hodgepodge Frankenstein's monster of a ship, built using structural spares made during the construction of Discovery and Atlantis and bits of the Enterprise. They figured that would be cheaper than dropping another cool few billion on a new ship, or else accepting a major American manufacturing conglomerate proposal to build two ships for the price of one (seems suspect to us, too).
Tom Baker is the Comics Editor at WhatCulture! He's heard all the Doctor Who jokes, but not many about Randall and Hopkirk. He also blogs at http://communibearsilostate.wordpress.com/