MiG-31 with "Daggers" will close the coast of Russia

via IZ.Ru

The naval aviation of the Russian Navy now has two military units armed with MiG-31 fighters. One is based at the Monchegorsk airfield in the Murmansk region, and the second at Yelizovo in Kamchatka. Repair of the runway in Monchegorsk was completed in October 2013. More than 2 thousand concrete slabs on the runway itself, taxiways and equipment parking lots were replaced. In Yelizovo, work on the strip was completed in the summer of 2016. Its length was almost 3.5 thousand meters.

With the advent of the “Daggers”, the fleet will be able to “reach” almost any region of the Arctic adjacent to the shores of Russia. New missiles are capable of hitting targets at a distance of up to 2 thousand km. Aircraft based on the Kola Peninsula will control the space from the coast of Iceland to the Kara Sea. And from Kamchatka, the MiG-31 completely covers the waters of the East Siberian, Okhotsk and Bering Seas.

Here. 

Ok.  A bit more of the same.  The Russians are going after the North Pole in a big way.  I get it.

What I don't get is the platform picked to launch this weapon.  Why the Mig-31?  I would think that an SU-34 would be the airplane of choice but it isn't. Why?