To be quite honest, I strongly suspect that the petition will not result in a major change of heart. I lost my faith in this government's response to petitions after the petition against per-mile road charges and the one against ID cards were both formally responded to by the government with "we don't care what you voters think, or even the science, we're doing it anyway, la~"
However, I do believe in hope, and I most certainly believe in democracy (or at least a republican system that approximates it). Petitions help to raise awareness of an issue, and help us show solidarity with those effected by this and those who are appalled by the decision.
It is better to try, and affect others through trying, than it is to not try at all. The ending of the poem 'Ulysses' springs to mind, the principle by which the enlightened must live...
One equal temper of heroic hearts,
Made weak by time and fate, but strong in will
To strive, to seek, to find, and not to yield.