To avoid this I constantly put a fine mist of water from a spray bottle onto the canvas so the colors can be blended before drying occurs. A heavy layer of paint will also help it dry slower.
One advantage of acrylics is that textures can be more easily made because once the acrylics dry, consecutive layers can be placed over it as a wash, splattered, and so on without it mixing into one flat tone as oils would. The pace of painting can be kept up without waiting days for drying to take place. The painting below is an example of the variety of textures that can be made in one sitting.
Here is what artist Jay Babina of Connecticut said on the subject.
I paint with both oils and acrylic. I believe that acrylic attracts many beginner artist because of the easy water clean-up and no fumes etc. I think that a greater percentage of this criticism is because of the lack of color and observation that comes with training and experience. There's just less highly accomplished acrylic painters vs. oil. Also, oil painters are constantly painting with contaminated pallets. The brushes are never clean and there's a greying down of pigments that is occurring constantly. Whereas with Acrylic, it's just easier to clean your brush thoroughly with a few seconds in the water. The mixing on the canvas of an oil painting goes on for a long time since it's always wet (for quite a while).
I often go to the library and take out the endless array of art books especially in the winter and rarely do you see acrylic painters in the books who are able to subtly use color. It seems to attract loud painters and very stylistic painters.