Why there was no government coalition between SYRIZA and KKE, from Syriza's standpoint

I copy from "Radical Initiative", SYRIZA's Union in National Insurance Corp; the article is by George Gialouris: 

The third option for government coalition was with KKE, but their leadership had rejected - and quite rightly in my view - any such scenario. SYRIZA is a party of bourgeois management that seeks solutions within the EU and wishes to find a path within the EU. KKE doesn't.

Of course, this doesn't prevent the surprisingly candid SYRIZA member from adding the ritual coda:

Nonetheless, [General Secretary of KKE Dimitris Koutsoumpas] should have met with [SYRIZA leader Alexis Tsipras], showing people that he is not the representative of a fossilized party, that he wishes to convey his party's views in a more media-friendly way, as he himself has stated that he needs to do to win people's trust [Koutsoumpas has never made a statement that KKE should be more "media-friendly"]. On the contrary, [Koutsoumpas] chose the path of self-shielding behind his intransigent ideology.

I hope this answers a number of questions on the issue, confirming the objective nature of the incompatibility between the two parties. It is fascinating that SYRIZA's own member admits to the exact characterization of his party that KKE deploys, and that SYRIZA pretends to be insulted with: as a party of "bourgeois management" of the capitalist-imperialist system. 

PS. On the illustration: The "Communist Organization of Greece" (KOE) was one of the constituent organizations of SYRIZA. On the day after the June elections of 2012, SYRIZA newspaper Avgi featured a cover where the hammer and sickle, barely visible in KOE's "updated" logo anyway (picture below), had been entirely removed.