How would it ever pass normal legislative process? If I tell you that you have spend two more years working and there's no benefit for you at all, would you vote for it?

Through parliement. Thats just how a normal democracy works. Or through a referendum.

unless we are talking about handling a national crisis, or avoiding a US-style shutdown, then avoiding a vote may be legitimate under specific circumstances.

but I doubt pension reforms fall under national emergencies

I agree it should not fall under national emergencies, but I don't see any other way it would pass. Nobody wants to work longer for no gain. The pension system in a lot of countries is basically a ponzi scheme.

Probably did it because the EU needs this for political acceptance. It should have been made clear to people, that any form of social security system will need to be harmonized. I guess this was just the first step to increase pension age and in general it will always converge on the lowest common denominator for normal workers.