Should public service workers be allowed to strike?
It depends on your point of view: Railway workers can hardly be classed as ‘vital public service workers’ in the same way that emergency service staff can, and in the UK the railways have been privatised, taking any notion of such classification out of the equation. Everyone should be entitled to protest about their working terms & conditions, but as you say, a guarantee of no redundancies in the current economic climate is completely unworkable. Vote with your wallet & avoid using the train services if you can.
Why do you automatically assume it is train drivers who are the ones going on strike? It is RMT members, which consists of station staff, signal operators, train maintenance staff as well as drivers. The majority of drivers are in ASLEF, who are not in dispute with London Underground and whose members will be working as normal. In answer to your question, yes, workers should be allowed to strike. I for one am against the reasoning behind this particular strike but many strikes are called because the TOCs try to cut corners with regards to safety measures. If there was a major rail disaster because tracks hadn’t been properly maintained then the anti-strike brigade would be amongst the first to complain.