The characters of an anime are intended to speak in Japanese. The Japanese voice actors are screened and hired to perform them. Dubbed anime is not able to give this much thought into picking voice actors. Due to the limited number of dubbing studios, there is also a limited number of voice actors, and as a result the same actor voices several characters across different shows.
Dubbed anime is a growing market, with large companies such as Funimation heading projects to dub more anime for international viewers. The trend of dubbed anime could grow bigger in the future, so it should not be shunned just because it is limited for now.
[P1] Japanese voice actors are able to provide the best performance that complements the original character of an anime. [P2] English dubbing studios are not as prominent as the Japanese voice acting industry.