For quite some time, I’ve felt that IT certifications on their own do not demonstrate the technical ability of the person. However, in a situation when applying for a job where the person sifting through resumes and the hiring manager are separate groups, having a certification can only help. Obviously if a candidate fits the supplied job requirements exactly, then certifications may not be required, however the candidate must be head and shoulders better than the next candidate with a certificate.
Generally the contractor or hiring process will narrow the field to a handful of candidates. In this culling process, certifications, college degrees, past experience, and how polished the resume looks are common criteria. I have been passed over for all of these reasons at different points in my career, and several times I knew the engineer that was eventually hired. I felt like I was a better engineer, but he got the job anyway.
Just because someone gets a certification, it doesn’t guarantee a job in that field. For example, I’ve known a couple people that went to community college and got their CCNA. Great for them, however they were fed all manner of half truths about the promised land of great CCNA jobs paying close to 6 figures.
I’ve also known several engineers that have never had a certification in their life and can troubleshoot almost as well as TAC. It just depends on the engineers background and mindset. Certifications don’t make an engineer, but they do show some initiative and some level of knowledge.