You have to continually recertify in-order to get the recognition since most of the certifications expires after a certain period of time of which it depends with different vendors. This is unlike degrees which are valid until cows have horns.
Those trained only in a vendor-specific technology may be less capable of evaluating alternative approaches to a problem.
An engineer with Cisco-specific implementation training would understandably be reluctant to recommend a competitor's switching model. This holds true even when there are clear technical merits in the alternative.
Some certified professionals are over rated by only the fact that they have an I.T certification without experience. They often say experience is the best teacher. It is becoming easier to get I.T certifications through the use of dumb questions.
Some certifications are very expensive to have therefore prohibiting deserving experienced experts in the field.. For example CCIE lab exam costs 1 500US$. So only people who are assisted by companies or certain priviledged people benefit.
5. High pass mark
In the certification world a 50% is not good enough to earn you an I.T certification. Most certification requers very high pass marks making it difficult to obtain.
A balance between professional or tertiary qualification and professional certification will make candidates more marketable in the job market