You have to be careful with this one. When someone has enough credibility, sometimes you need to question yourself if you disagree. If you are playing chess and Gary Kasparov comes along and tells you what your next move should be, you can disagree with him, and you might even be right, but given his expertise in chess, his move is most likely going to be better than yours and it's worth considering (unless, of course, you are chess master at his level). The same thing is true with software. Some people are really strong engineers with really strong expertise in a specific domain. If you follow their advice within their domain of expertise, you might not come to the optimal solution, but you'll probably come to a good enough solution. Of course, there are exceptions, but in my personal experience, I've seen more people mess up by not following experts' advice than by following it.