Open Source Software development model

define better first.

is it generally faster? yes.
is the code quality generally better? yes.
is the application more secure? yes.
is it more stable? yes.
is the cost of developing it lower? yes
is the cost of obtaining it legally lower? yes

Of course it is better ....

Why do you think we hate Microsoft and love Tux ?? why do you think we have so many Windows vs Linux discussions going on?? :D

]:)

Well it depends of your point of view.

If I would be a proprietary software developer with a 100% branch covering, I guess, that is an understatement, I would find the proprietary model the best there is.
Everybody in the branch is depending on me and my company, profits will be huge, can donate any amount of money to any charity I want, or not.

If I were the consumer/user/buyer of this software, well I would be best served if the cost of the software, buying and remodeling, are as low as possible.
If there was one 1 party where I can turn too to buy or remodel, I have the risk that whenever that company has the hick-ups, I will get them. Meaning I have to pay whatever they want me to. In the end they are in charge of my company's profitability. And as I am working for a governmental company in the end the TAX-payers will have to pay for it.
On the other hand if there is competition on who may develop for me, I can get the best deal, but what will work for me is the best fair deal. Special as everybody has to make a living.

Leaves this much to imagination... just ask and I will give the answer. (lol, not to all but fair question fair answer)

Rob

The principle reason is peer review. Making a bright and shiny app with spangly buttons, where the internals are a poor implementation of a crap design will not be successful in open source. Certain closed source companies make a pile of money out it though. Another reason for it being better is plain enjoyment, developers in OSS will fix problems not implement naf bodge on top of naf bodge because management are prepared to sacrifice quality in order to increase profits. So you spend more time show casing your development talents to your peers as opposed to your turd polishing ones to managment.
In closed source, particularly when you have a tied and large engough market share, the first casualty of developing is always quality.