In all of the above cases, Firefox actually does support the features used by these sites, and has for a long time (years, in some cases). In most cases the developers would just need to tweak their UA sniffing, or add some -moz properties alongside the -webkit properties in their styles.
Mozilla does need to "step up" -- but work required to fix cases like these is not technical. It's about gaining user marketshare, developer mindshare, and improving the standards process.
For some technical details, see for example http://bugzil.la/668218
Mozilla does need to "step up" -- but work required to fix cases like these is not technical. It's about gaining user marketshare, developer mindshare, and improving the standards process.