Common sense, if a small business is taxed on what the Liberals call "passive investments" while allowing big business to invest or diversify is just plain bad. Small business is the backbone of Canada and small business needs even more incentive to save and diversify. 
Then there is the whole regional aspect - a small business in the GTA is likely going to have much higher operating costs than a place in New Brunswick. 
How would the government offset that kind of challenge. 
My company needs to diversify and invest outside of the business and then when times get tough... and they will; it needs to draw from that investment to keep the doors open. 

This is how business works - its not some kind of evil tax avoidance and most small business owners i know are not as "wealthy" as the Prime Minister claims.