Why do you need to have an extra debate to discuss that? Why not just shrug it off like we did when Russia did the same to some members of congress?
Oh, it will probably be shrugged off. The parliament members in question still call for a debate though, which is their constitutional right.
You do seem to forget however that it is a delicate subject over here, since the vast majority of the dead passengers from MH17 were Dutch, and we have an official parliamentary inquiry commisioned to investigate it. Moreover, the information presented to us (the general public) about the investigations into the crash point more and more to the plane being shot down by seperatists, using a BUK supplied by, and hastily retreated back into Russia.
In that light, it does raise some questions like "what if any of those parliament members would have had to go to Russia if the parliamentary inquiry commission finds that nescessary for the investigation into the crash of MH17? Wouldn't that be obstruction of our investigation into the matter?", for which I'm sure our minister president has some satisfactory-to-the-parliament answers ready, and it will all go away quietly.
Besides that, it's not like some 'friend of the president' businessmen got banned from Russia, it's some democratically elected members of parliament that did. So to keep up the appearance of democracy to the general public, and satisfy their need of feeling informed, there is a call for debate.
EDIT: Our minister president just responded, and said he was "very angry". He called the list "without any legal foundation" and "will file a complaint in CAPITAL LETTERS with the Russian government".