Comment by josh2600

To be frank, when you are no longer the dominant player in a market, open source looks very appealing as a method of gathering additional market share. If you are the dominant player, there is little reason to give your opponents a tactical advantage by open sourcing your software.

Very few open source companies make money and even fewer companies make significant revenue as a consequence of releasing free/open software as their core business (FB/Google, for example, only open source ancillary services or services which devalue their competitors tactical advantages).