Harry Reid was doing this same exact thing during Bush's term well before Obama came into office.
Not sure if these "pro-forma" sessions were done during the Clinton years and earlier since I only started voting and following politics in 2002.
You're largely right, the difference beint majority versus minority.
Look, this is not a simple issue when it comes to the moral high ground.
Receess appointments exist at all not for getting around the approval process but as a practical matter when an appointment is urgently needed and Congress is out.
But then Congress sometimes blocked appointments for bad reasons - and Presidents used the power they clearly had but for other reasons, to 'do the right thing'.
As in the examples of appointing a black or gay person who was a great appointment, but blocked by bigots.
And once that was done, a worse president used the power get around Congressional opposition for GOOD reasons, for bad judicial nominees, John Bolton, etc.
And then as a result you had Congress blocking the President from recess appointments to 'do the right thing' to block the abuse of the recess appointment.
And now you have the Republican Congress trying to use the same thing for bad reasons, to block any functioning of an agency on behalf of the people.
And you have the President getting around them on that, to do the right thing.
So when you want to disicuss the right and wrong, there's a long way to go in that discussion - and the bottom line is Republicans abusing process and doing the wrong thing.
But as a process issue, the process doesn't decide right and wrong. What one party does with power for a 'good cause', the other can do for a 'bad cause'.
I don't see anything illegal here - the precedent of using recess appointments to get around Congressional opposition the president disagrees with was begun by Washington.
If you want to say things were wrong since Washington and the recess appointment should be removed altogether (directly or indirectl by allowing for 'permanent session' without any recess), fine, but then you are left with the things like Congress blocking nominees for 'bad reasons' from bigotry to political end runs as with Cordrey.
How then do you force the Congress to do its constitutional obligation of actually voting on nominees?