Here in the US, I have seen practitioners of other styles add Eskrima to their arsenal. Many people want to complement their style with practical weapons such as sticks and knives. The art of Eskrima also seems to be quite easy to learn compared to some other styles.
Eskrima should primarily be an ancient form of fencing. It definitely has those kinds of traits especially when it comes to long range stick fighting.
However there are also some very close ties to the art of Boxing. Filipinos take their Boxing very seriously and I have seen many Eskrima people add elements of Boxing to their training.
Since Eskrima has a strong link to Boxing, it's also easy to connect Eskrima with other styles that connect with Boxing such as Muay Thai and MMA.
When you examine techniques like the Heaven 6, you will notice that Eskrima has many similarities with Karate. After WWII Karate had a strong influence in the Filipino martial arts. From the Eskrima and Karate connection we can also link up with Kung Fu, since it is the predecessor of Karate.
The way I see it, is to train in Eskrima to get a better understanding of a different style, and to train in other styles to help you get a better understanding of Eskrima. Ultimately you get better at both. This is possible because Eskrima and other styles provide different perspectives of the same thing. If you get stuck in your training and you can't move forwards, then tacking it from a different perspective maybe the ticket for you to keep on progressing.