Multiplying them together certainly magnifies the effect, but it would magnify it the other way if the likelihoods were larger than one. (Easy to get, just tweak the variance of the normal distributions to be smaller). Likelihoods are more like infinitesimal fractions of a probability, that need to be integrated over some set of events to get back a probability. In the case of the joint distribution of 50 Gaussian, you can think of the likelihood having "units" of epsilon^50.