That's a double edged sword, proprietary software moves much much faster which is why plugins like flash came about. They plugged the gaps required that the web working groups couldn't agree on.
If proprietary was such a big disadvantage why would it exist at all?
Was it a disadvantage for all those people who got to play great games or watch video on the web for years before HTML 5 added the canvas or video tag? Would we have half the features in HTML 5 if they hadn't been proved by plugins or implemented as experimental by proprietary browsers?
If proprietary was such a big disadvantage why would it exist at all?