There is no particular demand as an artist in switching styles. Some artists feel that switching styles is a compromise position, whereas those artists who are selling their work feel they will lose clientele by switching styles. Locking in a style for consumerism is probably good for sales but not especially good for authentic artistic expression – long term.
We can cite numerous examples on both sides of the fence, those who have stuck to one particular style and those who vary their expression without concern for keeping a consistent style. Personally I don’t like being locked in to a particular style or genre of painting. I might paint a series of drag paintings which are completely abstract and these might take me through a period of six months. Then I might decide to paint a fairly realistic still life. I find that what I learn in one will often translate into a new way of doing the other. The discoveries I make with one style will positively affect another style or way of painting. I think this is a clear advantage. Locking myself to one set style seems highly restrictive.
I appreciate the fact that someone as famous as Gerhardt Richter has been willing to change his style. He will go through distinct periods where new work is considerably different than a previous one. I find this approach refreshing.