Well said kromo (and Nigel, for once!).
What people rushing to sign this petition should reflect on is this:
Currently, the government can just turn round to the Lords and say "stuff your vote: we are going to carry on regardless". And because the Lords are not elected, fundamentally, and regardless of what the rules say, no one is going ultimately to come back with any great moral force.
However, if an ELECTED chamber threw a spanner in the works, well then there would be more of a problem: and Brexit might be in (even more) trouble.