The election cycle does have something to do with it: in the last year of his presidency, he has nothing to lose legislatively by putting all his proposals on the table. In previous years, he had to weigh each of them against the cost of losing whatever he was trying to accomplish with Congress.
That's not Obama's fault; it's the nature of the system. The President can't do whatever they want; their hands are tied by the other two branches of government. Blame John Adams.
Outgoing Presidents still work towards the future electability of other members of their party over the alternatives - in Obama's case, Clinton or Sanders over the Republicans. That's part of the opportunism, along with, yes, saving the more controversial unilateral actions for when they no longer need to worry about their own re-election or cooperation from Congress.
Liberal Democrats can then feel better (via recency bias) about a party that continued the Patriot Act, Gitmo, whistleblower prosecution, etc ad nauseam, while the next candidate can appeal to the moderate right that "hey, that was the last guy."
My point though was that it would be a misconception that an outgoing second term President doesn't have to weigh the impact of their decisions on future elections, even if they themselves will never run in one again. They aren't truly free to just drop whatever policies they want with no consideration for how it will impact future elections.
This one is getting done precisely because it can work with that agenda, unlike other possible policies that I'd bet, deep down inside, he has to know would also be good for the country - e.g. rescheduling marijuana or ending the war on drugs - but that would have a larger negative impact on future Democratic candidates.
And I don't know where you have been, but the Republicans have repeatedly tried to destroy anything Obama proposed. I say this as a fiscally conservative person (i.e. i am with the republicans on the financial side but with the democrats on the values)
Why are you with the Republicans on financial matters?
I am a partisan Democrats and enjoy scoring points on the internet as much as the next fellow, but I'm also genuinely curious. From my perspective, the Republicans are extraordinarily financially irresponsible, all reputation and no substance. (It's like the old saying -- you get a reputation as an early riser and you can sleep in til noon.) They want to cut taxes, yes, but their proposals to do so all involve drastically unbalancing the Federal budget to do so. At their most serious, they include unspecified $XYZ billion spending cuts and then never specify what they would actually cut to close the gap.
Obama's deficit, meanwhile, has largely been the result of automatic spending increases from pre-existing legislation in response to the Great Recession; his stimulus bill from the first year of his Presidency was a small fraction of the increased spending on Medicaid and Welfare and SNAP as millions of people lost their jobs, on Social Security as people retired early, and Medicare as people deferred medical treatment until they qualified.
The ACA was funded, is costing less than projected, and is in fact controlling medical costs, which makes long term financial projections much rosier than they were ten years ago. There is no plan to replace it, and repealing it, as Republicans keep trying to do, would be bad for our short term and long term financial health.
Obama has significantly reduced the size of the Federal workforce (I am actually unhappy about that, since it probably slowed down the recovery).
So why do you consider the Republicans fiscally conservative?
Where they then want to spend is where the agreement stops and I end up being more democratic when it comes to values.