Board Thread:Questions and Answers/@comment-100.4.205.70-20180614150407/@comment-80.225.90.76-20180614204659

We don't really know why, but here's my guess:

The bloonchipper had very powerful stalling capabilities as well as being able to "process" MOAB layers very well. Rounds with lots of MOABs could be passed far easier with a few chippers. Also, bloonchippers make lategame a lot easier. TL:DR; they are a very powerful tower for both MOAB destroying and stalling.