Linux and Hadoop are not analogous. I've used Linux since the pre-1.0 days and been building distributed computing and database platforms since before Hadoop existed; I've seen both of these ecosystems grow from the inside.

Linux won the server wars because it rapidly iterated and evolved in a time when a free UNIX-like operating system was desperately needed. In the early days of the Internet, no operating system was ready to be a heavy duty Internet server OS. FreeBSD, started from a stronger position than Linux but development was carefully controlled by academic purists. Eric Raymond's "The Cathedral and The Bazaar" was about these two communities.

Operating systems, like Linux, tend toward natural monopolies. It is extraordinarily expensive to build a competitor. Linux was the most agile and rapidly evolving competitor in an early market that was poorly served by incumbents. While it took the rest of the world years to notice, it was obvious by the mid 1990s that Linux was on a trajectory to take over that market, not because it was good (back then, it wasn't) but because it rapidly evolved in response to user needs.

Hadoop is more like MySQL than Linux. It provided a very early option in a market devoid of options. Technically the implementation is poor and the details of these choices are exposed to users as features and interface. This makes it difficult to evolve the core because it pisses off the early users who have become used to the way it works. Linux had the advantage that it copied a good design (UNIX), which allowed it to iterate the core without breaking too much for users. Over the long term, these poor technical choices early on limit the ability to grow because fixing them alienates the users. MySQL had a strong run of dominance, particularly in the early days, but the inability to easily evolve into a robust and full-featured system allowed PostgreSQL to eventually relegate it to relatively niche use cases that can be easily replaced by other bits of technology (like NoSQL data stores).

Hadoop has one other quality that makes it fundamentally different than Linux. It is a relatively simple system that can easily be functionally copied. Making a Hadoop-like clone using alternative tool sets is not a big task. While very popular, it would not require an extraordinary investment to produce an alternative that is obviously superior.

Some form of Hadoop will be with us for a long time. It will always have a use case. But unlike Linux (and more like MySQL), it will ultimately be marginalized by its many manifest technical weaknesses. Not only is it easy to build a significantly better "Hadoop" than the free Hadoop -- many companies already have -- but there are some very important distributed computing technologies and features which Hadoop does not have and which would be difficult to implement on that platform even if customers want them. The larger NoSQL and distributed computing space is evolving very rapidly with many potential alternatives.

The only lessons for Hadoop from the history of Linux and open source generally is that it is in a ripe position to be marginalized over the long term. I've seen this hype cycle many times for products in similar positions. I remember, for example, when Perl was the programming language of the Web. Perl quickly dominated a void in the market at the time but where is it today?