davey.havoc1) Rip off or not, but most groupbuys for keycaps in GH, DT, MD, China forums, Korean forums, they all have supported layout for Wk and Wkl, hence they are dubbed as Standard Layout since it's easily available from most keycaps gb.
Wkl (Winkeyless) comes about because most of the older vintage mechanical keyboards uses that layout. For example, the infamous IBM Model M and some Cherry vintage boards. The early adopters of mkb likes the look of the vintage wkl keyboards and hence they have made it into standard due to popular demands and the availability from big keycaps manufacturers such as SP and GMK.
Initially the groupbuys for keycaps starts with Standard Wk layout, thanks to Moogle, and later on, thanks to Tsangan, somehow because of him we have Wkl kits available in groupbuys and now we can see most of the current groupbuys have Wkl kit included by default.
I have no comment on the Infinity keyboard as I didn't follow the start and progress of it at all, but I think it's a good step towards a globalisation standard for future keycaps groupbuys!

2) Yes, quality is subjective since it's a hit and miss for anything that is manufactured through mass production. 2 keyboards of the same make doesn't necessarily means they have the same quality. This applies to reputable keyboard maker such as Filco and Ducky as well, their products too have defects. I personally didn't own a Razer keyboard before, but this information is what I have seen across a few forums and reviews from users, the complains ranging from key chatter, dead led, malfunction board, and to the rubberized surface finishing starts to peel off. Kailh switch already has bad reputation from the start with it's switch being inconsistent and the stem easily breaking apart. To hear them making switch for razer's new line up is too much for some people, but to be honest I have yet to hear such horror stories from the "new razer" switch. I guess they have up the quality this time around.

3) I agree with you on this, they deserve the credit for the marketing hype they have created.
I guess this can be quite related to the eternal battle between Android and Apple, lol!

4) I have explained some of it in #1. Wkl kit/layout was introduced not long after Wk standards have been made into regular groupbuy. Most people who joins the groupbuy buys the Wkl kit as well even if they are not using it, because this makes it easier to resell them as it covers for both Wk and Wkl users. So there's really no problem or fragmentation for Wk and Wkl.
For the gaming layout mkb users, they can't really change the full keycaps because there's no 6u or 6.5u spacebars included in groupbuys, YET.
This will discourage them from buying/joining the groupbuys because they can't get a fitting spacebar for the colour theme of the keycaps groupbuy unless they don't mind having an odd looking spacebar. Due to this, it reduces the number of potential groupbuy participants as there is a lot of gaming mkb out there.
About the god tailo sifu thing, lol! There's fanboys everywhere. At the moment, the Koreans have the best custom keyboard designers, so their custom keyboard are very expensive and rare due to them making it limited editions. Some of the rare boards are extremely difficult to get even if you can pay for it as they make it exclusive only for Koreans. (If there's anything I dislike about Koreans, it's the way they make keyboards rare, exclusive and expensive, and also kimchi.)
I did mentioned though that changing keycaps is only important to those who likes to change keycaps, so yes, not everyone give two hoots about changing keycaps. Maybe only if their spacebar and wasd legend starts to fade/peel off like this, then they might consider.
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Personally, this is a deal breaker to me if I want to ensure my keyboard's longevity or 2nd hand resale value but I'm sure not everyone agrees with me.
Also, I like to have different look on my keyboard by changing the keycaps, which is a wallet breaker thing

Some of the points is what I gathered from various forums and reviews, not entirely from myself. I'm just interpreting and consolidating the information that I've seen so far, with some of my own thoughts into it as well.