If you look at destroying then the only thing you can destroy is Microsoft, Apple. Linux cannot die.
Sadly it can. When Linux will be replaced by some proprietary software on PCs, embedded devices, in HPC. Then, we can probably say it died. However, it seems Linux is the most healthy player out there.
I'm more interested in Linux remaining a stable and viable desktop platform than becoming popular.
As long as there is a fully functioning, Free (!!!) modern desktop and a high-quality Unix-like system underneath, I'm happy.
I don't particularly care if it has 1% or 90% of the "market". And I dislike attempts to make Linux less functioning and less Free just to appeal to people who don't care about Linux in the first place.
The most important questions are : Is it good? Is it free? Is it interoperable?
The last issue is the only one that is related to the market share. Luckily, OSS programs are becoming popular on closed platforms too (such as Firefox and OOo), so interoperability is less of a problem than it used to be.
I don't care about how trendy it is either, but don't forget that with bigger adoption comes bigger hardware support. The more it is used and the more the OSS paradigm spreads the more hardware vendors will feel the pressure to release drivers for Linux. Or so I want to believe.
I've just recently started using Linux (Ubuntu 10.04) at my new job, and I really like it. I think it should be getting more popular, it's easy to use, and even easy to install and dual boot on a Windows computer.