Why does retail launch last 4 expansions flawless, whilst classic is a bug fiesta?

Try asking the more than thousand guilds who lost almost everything in their guild banks during TWW launch if that was a flawless launch …

Here, three months after first TWW patch the guild banks are still empty and Blizzard are not restoring items - or even communicating about it. They just hope to sweep this major data loss silently under the carpet.

So much for a flawless launch …