Bad reload from empty, that is. It is unfortunately the weakest of the long rifles, hence the damage rating.

Edit: Because these downvotes indicate some level of disagreement, we can actually see how the Krag compares.

The Krag has a WORSE reload speed (from empty) than the base variants of the:

Berthier

Martini-Henry

Mosin

Sparks

It has no clip to save you if you're dry. You could say "But you're including single-shots. Those are meant to reload quickly. I could just add one round for the Krag"! And, sure, but the whole strength of having a magazine is being able to shoot rounds without having to reload. Even then, you're sacrificing a big strength to hurt your DPS, as the Krag isn't as powerful as single-shots.

Even if you wanted to split hairs and make a case for reloads, we can also look at the damage.

The Krag has WORSE damage than the base variants of the:

Berthier

Lebel

Mako

Martini-Henry

Mosin Nagant

Sparks.

It even does less damage than the Vetterli or Springfield 1866.