The same MPs who clamoured for Vaz to sit on the Justice Committee are now clamouring for him to stand down
As far as I am aware no MPs "clamoured" for Vaz to sit on the Justice Committee. There were two vacancies which the Labour party needed to fill. Only two MPs put their names forward for these vacancies. He was one of them. He therefore got the role. The fact there was a vote in the Commons at all was highly unusual. The article to which you link mentions two MPs calling for him to stand down. One of them voted to oppose his appointment and the other abstained. Neither of them can in any way be classed as "clamouring" for him to sit on the Justice Committee.
So your statement is completely untrue.
Sometimes our MPs do behave in ways that seem out of touch but their reputation in this respect is not entirely deserved. Sometimes they are misrepresented in the press. And sometimes people are too willing to believe things they see on the internet. I remember, for example, a composite photo circulated widely on social media a year or two ago purporting to show the Commons packed full of MPs when discussing their own pay and expenses, and almost empty when discussing other important issues. It was a lie. The photos did not depict the events stated in the captions.