The counterargument is that the FIT is set by government regulation, not by the market. In that sense it is little different to the ethanol production credit. The producers are probably getting paid too much. I suggest feed-in tariffs be removed after a few years to see what customers really want to pay. Alternative incentive schemes include green energy quotas with no price support
http://en.wikipedia.org/wiki/Feed-in_Tariff
Electricity suppliers like hydro do very well in spot markets; in Australia recently spot electricity sold for $10 a kwh, that's 1,000 cents a kwh.

There is also an equity effect with FIT in that the poor (pensioners etc) stay poor and the rich (corporations etc) stay rich.

It isn't a counter argument - it is an argument. Electricity rates are already controlled by government regulation, from pollution controls to allowable margins. Simply extending that authority to foster competition, for reasons that may not be 'market oriented,' simply allows for the fact that the 'market' is not the only factor in deciding a society's interests, however imperfectly.

As for the rich getting richer in their position of the owners of capital - that remains true in both cases, the only difference being the scale, not the reality.

Solar panels on the house provide electricity transmission as well as electricity. Every kilowatt on site is a kilowatt that isn't crowding out the kilowatt for your house in the transmission line and heating up the transmission line. Lower transmission line temperature is lower electricity losses and lower chance of overload blackout.