The big problem with any attempted assault on any platform business is the difficulty of dislodging formidable competitors with strong ecosystems (Apple, Android). Conversely, platforms unable to keep can decline rapidly (witness BlackBerry, HTC, Nokia).

In the operating system market, upstarts, often with tacit encouragement from mobile service providers, are attempting to displace some significant market share from Apple and Android. It is not proving especially easy, nor do even proponents think that will be the case.

Tizen, one of the proposed new operating systems, has gotten at least a temporary setback as NTT Docomo, which had been moving towards adopting handsets using Tizen, now has said it will not do so.

Telling are the reasons why: “there is not room in the market” for three major operating systems, “at this time,” NTT Docomo said.

Separately, Canonical, supporting the Ubuntu operating system, say no launches are expected until 2015, at the earliest. For the most part, the upstarts are using open source approaches. Only Microsoft is making gains, based on Windows Phone.

In fact, many observers predict that Windows will be the third largest operating system by perhaps 2017, trailing Android by some margin, but close behind Apple. Others might think Windows has a shot at surpassing Apple.

The point is that, “everybody else” might have to share perhaps five percent to six percent market share by 2017. Whether such small shares are sustainable over the long term is questionable.

Mobile service providers might well prefer there was less concentration in the operating system realm, to give them more leverage over handset suppliers. But that might not be a realistic hope, long term.

In most other parts of the communication business, a long term “rule of three” typically does develop, with market segments lead by about three providers. That is going to prove challenging for regulators typically more comfortable with the notion of four leading mobile providers in any single country.

Whether that is sustainable, in most countries, over the long term, is the issue. A reasonable person might argue that, eventually, a stable market, generating sufficient financial returns to support robust investment, will happen in markets with three leading mobile providers.