Microtransactions are still kind of a new thing for companies and they're all piling to milk the fat cow. This can be handled well or it can be handled badly, but just offering "Rose Tinted Glasses" to your avatar for real money isn't going to destroy the game.
You know what else was "kind of new thing"? Credit Default Swaps. And companies all piled in to milk the fat cow, while general public was donning rose-colored glasses. "Interest-only mortgage? Sign me up! How can I possibly lose?!"
Just like banking, gaming industry, especially MMOs are confidence games. Once customer base loses confidence in the product and/or developer, the collapse comes quickly and irreversibly.
The fact that you can legally buy ISK in Eve is an interesting conundrum and one which has already existed in-game (without causing server wide chaos) for quite some time.
First of all, PLEX != Microtransactions. Those are completely different animals. PLEX to ISK and back to PLEX are transactions between
players that are merely guaranteed by CCP. One player essentially pays for the time of the other. In MTs, CCP conjures up an item out of a thin air, and then this item enters the regular ISK market.
Blizzard can milk the MTs because their games do not have massively complex player-based economies. CCP has demonstrated time and again that they have frighteningly little understanding on how their actions will affect game world (one latest example being Dominion, where Sov changes caused exactly opposite effect that was intended).
I say the jury is still open on how that plays out, but the fact that there isn't rioting on the streets is one indicator.
There was no rioting on the streets when CDSs were issued either (expect for few economists screaming bloody murder), mostly because "people on the streets" are too dumb/busy to understand long-term effects of such changes.
