What do you mean "too weak"? It's literally impossible for the President to push through a judge who the Senate refuses to even vote on. There's nothing Obama, or any president, could have done. It's not within their power.
The thinking on this is that the rules, arcane as they are, say the Senate must “advise” on the Supreme Court pick (or something to that effect). So the argument is that Obama could have said, well, they were given an opportunity to advise and decided not to, so I’m going to fill the seat. The legality of this is grey, but it was discussed a bit at the time.
Clearly Obama should have just done an end-run around Congress, because that's how democracy works in America now, right? Just write an Executive Order and ignore the fact that it's totally and completely illegal. That would show "true grit," breaking the constitution and all...
There was a time when I'd have considered your comment snarky. Now it almost comes across as sage political advice for the modern USA.
Obama set a precedent for that type of executive. Following a growing trend as the congress has become so bi-polar.
Used his political (not official) powers to shift the public discourse more effectively. He did not make much effort to attack McConnell's brinkmanship.