Even though both of them would make terrible presidents, Clinton is the pragmatic choice over Sanders because Sanders is a complete socialist. Clinton is only mostly a socialist, so she would at least be the lesser of the evils. Bill Clinton, in all of his glory, was far more of a centrist than his wife. It's a shame that more people didn't see the gem of sanity that was O'Malley.
While many of Bernie's ideologies are appealing, they are not realistic. In order for Bernie to make the many, many changes he promises, he would need the support of the House and the Senate, which he most certainly will not have. Hillary's slightly more "moderate" views on the issues make her a candidate that is more electable in the general election and one who is likelier to create greater cooperation in the capital.
It would be smart of Hillary Clinton to present herself that way, but her positions aren't necessarily more sensible. She prefers to keep things the same, while Bernie Sanders wants to change things that he sees as unfair and wrong. While it may be slightly unrealistic to actually change these things in practice, it isn't unreasonable to think that they need to be changed. If a candidate in the early 1800s wanted to abolish slavery, an opponent might think that's unrealistic, but it doesn't make the opponent that won't try to abolish slavery more pragmatic.
Hillary was the flavor of the day along time ago and now Americans realize that she is so yesterday. Look this woman has all the ties in the world to politics but it's also clear that she can't handle that kind of responsibility with all the issues she's had in the past. The more pragmatic candidate is Bernie Sanders because he's about equality for all and isn't that what everyone in this country wants?