While many collectors would find the CommTech R2-D2 more desirable, the real reason why certain figures get rehashed over others is a little more complex than what collectors want. So, why did we get this R2? It was most likely because of factory issues. Different factories produce different figures, and also have different tooling.
In the case of most of the Hall of Fame wave figures, there was an effort to consolidate production to as few manufacturing plants as possible. Hence, we've gotten the POTJ R2-D2 instead of the CommTech one. Likewise, we've also gotten the POTF2 "All New Likeness" Princess Leia instead of the POTf2 CommTech version.