For ordinary people absolutely to follow one guru all the way is the best especially for spiritual path as per reasons mentioned earlier by everyone.
I just wondering that people who looking and searching for the 2nd, 3rd teacher, is it because they are full with ignorant and have wrong view thought that to have more is better, like to have more houses, cars, properties etc?? poor thing, some of them even do not want to listen other advise and still hopping and searching for new guru all the time.