On a personal level it is sad to see a career unravel, but Lord Sewel can blame nobody but himself. What this does bring into sharp relief is the irrelevance and unsuitability of the House Of Lords as an institution of government in a country which bestrides the world claiming to be a democracy. Originally a seat in the Lords was an honour you inherited when the aristocracy was a power in the land. The industrial revolution opened up the opportunity to get a seat through money. The modern method is to get there for rather vague reasons to do with charity, sport, business or whatever. Also through politics. Here the route is far better defined; rejection, failure and old age.
If things were ticking along just nicely we could perhaps totter on. But the Union in the UK is by no means secure amid arguments over devo-max, English votes and an underlying resentment in the three smaller nations of the predominance of Tories in England, when elsewhere their representation varies between little and nil. The premises of the House of Lords would be ideal to house a UK Parliament, elected by universal franchise. It could also be the revising chamber for all the National parliaments, including the English parliament which would occupy the present House of Commons.
As for the Noble Lords, just send them home. If they would like to come back they would have to do so individually backed by a mandate of the people. They would not thus be ennobled, but they would be modern elected democrats. They would also have to behave.