It's true that at the moment, solar panels have only just passed its energy break even point. That is, the entire development and production of solar panels, with all research involved and the energy consumed with producing panels, it has, up until a few weeks ago, cost more energy than it delivered. And of course, it's by far not economic yet. But what you're forgetting is that it will be.
A place where this technology has proven very successful, is on places 'off the grid'. Think about small ocean sail boats, log cabins in remote places. Generating power far from civilization is quite useful, and solar panels are perfect for this.
In 'normal' homes, the benefits are small at the moment. Yes, you'll save on your monthly power bill, but you need to invest quite a sum of money to be independent from the grid. And yes, at night you would need another source of energy, or you need a battery system. And all battery systems are pretty low in efficiency and capacity, and very environmentally unfriendly. Putting power back in the grid can be done, but is often tricky and hard to get money from. But governments promote it, since it's still a favorable source of energy compared to burning coal or other fossil fuels which have larger impact on the environment.
And what people often forget is that oil and gas is inevitably going to get more expensive. I'm in the oil business, and I can tell you that there is still a lot of it around. But the problem is that it's in countries which are not so eager on sharing (read: middle east and russia). Nonetheless, as we use up the 'easy' oil we can get our hands on, prices are going to go up, because oil will become more scarce. And harder to produce, which will drive up the price as well. That will make solar/wind/biomass or other renewable energies a lot more attractive.
But we can't sit around and wait for the price to skyrocket without developing the renewables. That would be catastrophic, once fuel prices go up there won't be much time to develop everything.
So, that's why there is an incentive to promote the use of these sources of energy. And then you can call your government stupid, socialist, or whatever, but you're the one that's not seeing the whole picture.
