Why does Mark get blamed for jilting?

I also would like to know this

Sophie, family & friends would immediately be on her side and spin a version of events that would portray the disaster as entirely Mark's fault. I don't think anyone formally describes Mark as a jilter, in fact it was in part due to his fear of being described as such that he went through with the service, albeit miserably. However hiding in the rafters, behaving as though he's waiting to receive a prison sentence and bursting into tears during the service seem to be enough ammunition needed for Sophie and the Mark haters to cast him as the villain. Besides who was going to speak up for Mark? Flaky Jez? Crack addled Super Hans? Half mad Johnson?
For the record I think he was better off out of it, but only just.

It's a little complicated. If you're a boxing fan you know the meaning of a TKO (technical knock out). A TKO does not mean you literally knocked out your opponent, just means you roughed him up enough so that he's likely defeated. Same goes for a TWJ (technical wedding jilt). Tell your best mate, bride's mother and bride's father you don't want to marry the slag then show up late for the ceremony and you have a TWJ. So yeah, Mark jilted Sophie in a technical sense.

He killed sixteen Czechoslovakians. Guy was an interior decorator.

I don't think he jilted her at all. Technically he was just late since he did marry her. I don't see the confusion. Of course that's not what she is going to say.

This is a ridiculous question.

If you've seen the episode, you can't help but have seen Mark and Jez rumbled hiding in the church when Jez pisses on the congregation.

Sophie absolutely wanted to get married - she's crying during the vows and afterwards as she's just seen Mark - her husband to be - was clearly trying to avoid getting married! Not exactly fairytale stuff...