The more comfortable people are with tools like DTrace, the better they will be able to write and use software.
- If you use Dtrace to troubleshoot a problem it's way beyond your scope of knowledge as a web developer. Dtrace is too deep and very specific to certain problems that you will never see because your regular nginx + php works fine in all cases.
- Not everyone wants and should be good at everything.
Just be good at what your doing well, I'm not saying that one shouldn't be curious but Dtrace isn't "an excuse" to install *BSD as a web dev.
DTrace is not hard, it's essential; and it's significantly easier, than say, awk, which is another crucial tool.
I think only Solaris has full support?
And DTrace in particular is really, really easy to use (the Linux alternatives, not so much).
Other than Dtrace... Tools like dtruss & co are not as clean as strace, that's the feeling I've got when I had to trace some calls.