Regarding 'no real power', This is often said but its not true. There have been occasions the monarchy have used their power but it goes largely unreported. One such occasion is 1975 in Australia where the government was thrown out using the monarch's power. The monarch hardly uses this power but it does if things go awry.

Also the 'consuming public tax dollars' argument is incorrect. The monarchy of the UK pays net tax-in through a deal the government did with monarchy 300 years ago (in short the UK government earns a tidy profit (about £300m/y) from the management of their estate in exchange for a small stipend each year, consistently renewed every period). The monarchs of other countries also have their estates that pay for them in a similar way (don't count Spain though)

Perhaps the monarchs favour the upper class though this has changed largely for the positive over the past hundred years. I would hardly say that today it is an unfair aristocracy, though.

On the democracy argument, there have been multiple referendums to put in place a republic but they don't go through.