You're actually very wrong. Long complicated passwords are horrifically impossible to remember causing people to write them down or store them in managers with simpler passwords to open the manager.
Putting them in password managers is the right thing to do.
Length is all that matters for passwords. You're better off with "thatswhatshesaid" (26 ^ 16) than "B4c0nL0v3r!" (72 ^ 11). You're 162 times better off, in fact.
26 ^ 16 = 43,608,742,899,428,874,059,776
72 ^ 11 = 269,561,249,468,963,094,528
You're wrong. Hilariously so.
The entropy of "thatswhatshesaid" is far lower than 43,608,742,899,428,874,059,776. Randall Munroe calculated correctly in the XKCD comic, of course. He didn't assume that each letter was random, he assumed he was choosing four words at random from a dictionary of a specific size (about 2048 entries == ~11 bits of entropy per word). Your password is clearly not a selection of randomly-chosen words, and even if it were, it would likely have been from a much smaller dictionary.
This highlights the danger of asking users to pick passwords... even those who think they know what they're doing are likely to screw it up. Munroe's advice in 936 was good... but I think it has mislead more people than it has enlightened.
No, it's much better to use a password manager and let a computer pick large random passwords for you.