There is nothing against emission reductions for other reasons than climate change (and there are many good reasons).
That said, I think it would not be wise to entire decouple energy policy from climate policy and climate science. The issue of climate change has more urgency to it than many of the other reasons for decarbonization (though I don’t know the ins and outs of all these issues of course). Besides, it strikes me as odd and counterproductive to leave aside a very important reason for doing something. There are more and more voices that claim that it would actually be productive to do so, but I remain unconvinced. The endless argument about whether climate change is serious enough to warrant energy policies would indeed stop, but at the cost of lowering the incentive for such policies.
The risk of doing something for the ‘wrong’ reasons is that the ‘real’ reason will not be sufficiently addressed. E.g. other solutions may be found for the ‘other’ problem and then the problem that really needs addressing, but that was strategically left out of the reasoning, is left unchecked. It carries the risk that not enough is done, or not fast enough, or that it will be stopped if other solutions are found for the ‘other’ problems (e.g. new fossil reserves; better filters for pollution; improvement of the geopolitical situation, etc).
Which issues are more urgent is a valid question of course. About the fossil reserves (and the associated ‘peak oil’), it’s worth noting that the conventional supplies of oil will likely still last for, what is it, 50 years or so. There’s still plenty of coal (which could technically be transformed into a liquid, alleviating the problems of ‘peak oil’, though it would be environmentally and climatologically disastrous). Then there are unconventional fossil fuels, including oil. I don’t see how the fossil reserves could carry the same sense of urgency that I think climate change has. Socio-economic impacts of peak oil, maybe, I don’t really know. Declining fossil fuel reserves are a very important motivation for technological innovation, but not so much for starting seriously with emissions reductions by deploying existing technology.
The ‘no-regret’ options for dealing with climate change are a good start (which have been postponed for long enough already), but not enough to get us on a climatologically safe trajectory. Climate change is too important of a reason to be left out of the energy policy debate.
[Update: Picture added (again) as it seems to fit the topic of this post just too well.]