Hi there Nathan Williams, how you doing? I just watched this video and I would love to share with you and the CardsChat community:
https://www.youtube.com/watch?v=7qcCTF9WUog
Well, your analysis is perfect, and I see why 97% of players would never fold to a situation like this.
Just for the record I don't believe it will be plus EV to open raise 22-66 from MP 100% of times. I will be opening two or three combos of low pocket pairs at maximum out of position ina Full-Ring game, because I know how tight these guys are (or loose).
But, it is really okay when we open a small pocket pair and get called by a Tight Passive player in the BB. We should know here how much this player is 3-betting preflop, it seems that it 3-bets only the top of its range, something like QQ+ AQs+
That being said, many players have a very flawed line of thinking the game, and this is the line: "I raised preflop and the villain called out of position. So villain would never have AA, KK, QQ, AK, AQ, etc because it would be 3-betting these hands".
Yes, it is true, at the micros players 3-bet almost 100% of these combos, and most of times burn them into preflop bluffs, raising these juicy part of the range against nits who fold a lot to 3-bet preflop.
Against MP, if I am in Villain's shoes, I would be inclined more to 3-bet than calling here, because TT will not play okay versus MP's range, even when it hits a set. So, I guess I would be 3-betting 4 combos of pocket T's or even 5 combos and calling down just one, when I see the player has a very wide range from MP and loves to bluff postflop (by 3-betting we take initiative upon the hand and can take the pot down much more times than if we call)
Now, in Hero's shoes, with pocket 5's it is very nice C-bet flop, polarizing its range a lot for value, and expecting to be CALLED by KQ, KJ, JT, AT, KT, and a lot of pairs (A5 not so much).
Because we are in position, and we already made a very intense bet size in the flop and we get raised a little more than 4x, it is very, very scary.

If we are facing an aggro donkey it is lovely because we know this guy will have so many bluffs, and Ax trying to bluff that, even so, the call could induce more bluffs.
So, if we are calling down versus a bluffer, with a very strong value hand, why not call with a tight passive player, who doesn't have too many bluffs in its range?
I would call this flop crying, I say, to fold many turns and rivers stupid aggression, like a giant polarized C-bet.
When I decide to re-raise, 3-bet I don't know, the 4x raise of the BB, we are repping the nuts, which is AA, because we opened preflop from MP, and it is more likely that MP has a lot of A's than the BB.
I posted here many times, but many players simply do not understand the basic difference between the nuts and a value hand: they play a value hand as it is the nuts or if it is a bluff most of times

Even if the player in the big blind have the second nuts (TT) or the nuts itself (AA) it will have only 6 combos of each, which are 12 combos. This also could be a flawed reading of the player, because the mathematics is very simple: There are only 12 combos of pocket pairs that are beating the 5's set, so it will have dozens of bluffing combos, when the player actually have no bluffs at all!

I disagree with the action of the player in the BB, a lot! The player in the BB doesn't have the nuts to be going shoving a flop like this! So, we observe that even deep stacked players do crazy things. And for the times the MP had bluffs, draws it will be leaving them all dearly! By calling a raise with a second nuts here, we are almost sure MP is going to fire again and again we could be calling very easy.
But maybe the player in the BB knew that the MP player would never fold a bottom set, two pair, I don't know.
The only hand that could be paying this all in flop is AA. All the rest should fold, given how passive preflop and postflop our opponent is. BB is only looking down to its hand and "omg, now I am rich I have the best hand possible for this board", when, in fact, it doesn't have.
I repeat, I would only call flop very sadly and then fold many turns and rivers if the pot geometry goes insane. But is is hard for players to leave hands! Thank you very much Nathan Williams!
Regards;
Carlos 'Aballinamion' Barbosa