Ventajas
Probably the best reason was that it was (and still is) a market leader and set the bar for innovation in the space of Data Management. It still is after all these years (somehow) an independent and as such Informatica is able to set the direction in which all others follow. Being an independent gives it so much freedom to direct the product in whatever way they see fit and a lot of the time these decisions were quite good.
Desventajas
Back in the day Informatica hired bright out of the box thinkers, somewhere along the line it became all about the politics, you play the political game well, you will achieve a lot. Also be prepared just to follow the words and desires of the people you report to, independent thinkers are just not listened too. If you are innovative and care more about your customers than the numbers, you probably wont do well at Informatica.