Saying "Linux" (which is a kernel, not an operating system) is unreliable because Konquerer crashes is like saying Toyota builds crappy cars because the stock windshield wipers only lasted a few months before needing replacement.
Linux (the kernel) is VERY reliable, especially compared to Windows (the kernel.).
The Operating systems built on the linux kernel (i.e. linux distributions like RedHat, or Debian) are also VERY stable and reliable.
Some of the applications included are not so stable or reliable. They are, after all, free.
Test them and find the ones that work and ignore the other ones. You'll still have more quality, reliable software installed than a default windows install (i.e. almost none in Windows.)
Generally when I see someone saying they're an expert and saying linux is unreliable, I find that both of those statements are overstated. I.e. linux is more reliable than they think, and they're much less the expert than they think they are.
My Linux workstation has an uptime of 51 days, and is busily burning CDs whilst playing mp3s while I type this message while it acts as a development server. No hangs, no problems.
Now, if your hardware is shit, you can't blame linux. Test your memory (memtest86.com) and look for bad bits. It's quite likely you have some in your machine. Linux is good, but it can't make up for bad hardware.