Periodically we go through this discussion about Genesis "going pop/selling out". A lot of good points have been made above and I want to echo some of that and add a few points.
Genesis has always tried to write songs that would be popular. As mentioned, The Silent Sun is a pretty blatant attempt at a single in the style of its era. Happy the Man and IKWIL are examples from the early 70s. However their attempts at pop didn't really connect with a larger audience until probably Follow You, Follow Me. And then they just kept connecting more and more successfully. At the same time they also kept creating more challenging songs that were not going to be played on pop radio.
I think it is actually quite hard to write a pop song that really becomes a big hit. There are always people trying to write pop hits and most fail to be successful. Writing a simple song might sometimes be simple, but writing a simple song that lots of people like is not so simple. And it is a particular talent to do this repeatedly.
And I'll say again that writing music to make money does not have to compromise the quality of the music. Some of the greatest music of all time was written to order, on commission with specific expectations. Many of the songs that stand the test of time were written very deliberately to be hits. The quality of the music has more to do with the artist than whether or not there was an objective to make money.