I don't agree with the article in the interpretation that the things at the top of the Maslow pyramid are less important (or difficult to empathize with) than the things at the base. Now, admittedly it has been years since the last time I studied the pyramid, but if I'm not mistaken, that model stated that all of the needs presented were equally important and neccesary for the well being and development of the individual, but the things at the base were the ones with the most
priority to fulfill because the inmediate survival of the individual depended on those. The article is right in that it's impossible to fulfill the needs at the top without first taking care of the needs at the bottom, but that doesn't mean the things at the top are less important (just less urgent), because ultimately every human being aspires to accomplish all of the levels in the pyramid.
That being said, I found the article fun to read, not to mention that it manages to make a very good point regarding Mary Sue characters and what is the real problem with them. Ultimately, it's not really the idealization or self insertion element (after thinking about it for some time, I have concluded that most fictional characters are idealized in some level or represent certain facets of the personality of their creator), but rather that they tend to dissipate the conflict in a story. It's really a reaffirmation of that old writing maxim ("meaningful conflict is the heart of good drama") but a good one.
It also doesn't help that some characters with certain conflicts just don't age well unless you present new ones (example: Superman)
That's a good point. Even then, I have to agree with one point of the article: When managed right, even characters as overpowered as Superman can be interesting. The key is to provide them with the proper sense of humanity in order to made them relatable (as the article puts it, give them conflicts and needs to fulfill that we as normal and common people can relate to).
"All Stars Superman", for example, being a tribute to the Silver Age, presents Superman at the most overpowered he has been in years (if not decades), and yet manages to make him a really relatable and sympathetic character.
It does it by putting him in a situation that contrast his overworldy super powers with a sense of humility and mortality. During the story his remaining time is limited, and the core of the conflict is not really about him finding a cure for the illness that is affecting him, but rather about him taking care of all his remaining business and making sure that everything is in place when he is no longer around. That is something that every person can relate to, because at some point in our lives we all discover that we have limited time and that we have to make the most and best of it while we can.