There is uncertainty in getting your claims through. Also, a lot of companies in recent years have been audited and have been asked to reimburse claims, although they had a record of claims going through. The CRA themselves, a couple of years ago, said in one of their reports that about 50% of SMEs don't even claim SR and ED, either for a lack of knowledge or because they think it's just too complicated. There's a mix. It is quite complicated, because it's all in the interpretations.
On May 31st, 2016. See this statement in context.