I'm glad Lee Sedol is back to that spelling instead of Yi Se-tol or whatever it was (I tried converting Sensei's Library some time ago but gave up due to pushback). I know JF may say those are more technically correct or accurate to the Korean pronunciation, but Lee Sedol is how he is, and presumably wants, to be known in the West given that's the romanization used in his books, the AlphaGo match, Go 9 dan server (which he was involved with), his facebook page etc. And as Kirby quoted, the vast majority of Koreans with his family name still call themselves Lee.
Your misrepresentation is just encouraging kɜbi (no r for me - see also below -) to be silly again. I don't think I've ever said any form was more "technically correct" - I don't even know what that means here. "Accurate" is inaccurate. And your implication I was doing the "pushback" on SL is, I hope, just carelessness.
What I did say
at one time was that McR romanisation was used in the GoGoD database for several very good reasons, one of which was that it made conversion to the hangeul form possible, while other popular romanisations didn't. That mattered then because Unicode wasn't available for most of us. It is now, so that reason has lost force. There have also been interventions by the Korean government since then. But none of that necessarily justifies a change in GoGoD practice.
A good part of the reason for not changing at GoGoD is that we do not impose any one version of a name - we offer all the sensible alternatives. The current Onomasticon (over 4,000 entries) offers each name in English, kana, pinyin, hangeul, simplified Chinese characters, Japanese characters and traditional characters. Furthermore, variant characters are shown and any variant English versions (such as Lee Sedol) are also listed. You make your own choice. I have made my own choice for the GoGoD database. The most important criterion has been consistency.
To go through (and reject) the reasons you list:
1. "the romanisation used in his books, the AlphaGo match, Go 9 dan server (which he was involved with), his facebook page etc" If we follow this logic, we would be saying e.g. Yuta Iyama, Yuhki Satoshi, Jun'ya Ohba for Japanese players who like to follow western practice (they also often favour the Japanese national romanisation rather than Hepburn, giving e.g. Tuda instead of Tsuda)). Of course some Americans already do say Kaiho Rin and so on. One problem comes when you deal with historical players (as GoGoD does heavily, of course) where there is no western practice. Are you going to say Sansa Honinbo and how would you handle Inoue Genan Inseki (or Gennan as many Japanese prefer)? And how do you rule on Fujisawa Shuko which the man himself so disliked? After all, it's on some books published on Japanese.
2. "And as Kirby quoted, the vast majority of Koreans with his family name still call themselves Lee." South Koreans - North Koreans prefer Ri. But this is a bit of an anomaly. There are some names where a particular westernisation does dominate but an awful lot more where variants battle for dominance. There are several pros with the surname Paek (White), but in English texts I have observed Paek, Baek, Back, Bak, Baik and Bek (there are other forms outside of go). If you add in variants of the given name, you get an explosion of forms. E.g. 9-dan Paek Seong-ho has appeared as Baek Sungho, Baek Seongho, Baek Soungho, Bak Soungho, Back Sungho, Paek Sungho. Another common example is Cheong/Jeong/Chung/Jung. And although Kim dominates, Gim appears to be making headway.
Even where a player's own preferences are known, it's problematical to follow them if consistency is prized. Historical (and some older people of more recent times) have never had, or wanted, a Romanised name of any form. There is no fixed pattern in modern usage to follow.
A minor problem comes with the name Pak, almost always romanised as Park. Which means many Americans pronounce it with a reflex r as in kɜrbi - though r is not correct in IPA, surely (and southern English make the vowel too long). Clearly it's problematical, therefore, to try to use pronunciation as a criterion.
The latest official romanisation is also of no help: it was designed for tourists and is ignored by the natives.
Chinese throws up problems too. Although the habit of putting the surname last (common when Hong Kong was the gateway to the west) seems to be dying out, there is still some variation with regard to splitting and capitalising given names (Nie Weiping/Wei Ping/WeiPing), and some Chinese think it's useful to take a western name for use in the west. The biggest issue, though, is with Taiwanese names. They tend to reject pinyin and use Wade-Giles, but often with idiosyncratic variations of their own, as in Korea. Do we accept that and used WG for Taiwanese players and pinyin for mainland players? (I don't, but couldn't really quibble if you did).
There are many more issues to do with names and no doubt things will happen in the near future that will change some of the current reasons for making choices. The GoGoD view therefore is to try to offer
all the choices but to strive for consistency, not just internally but also with legacy items, when making its own choice, as in the GoGoD database.