I've heard several good players make this statement and frankly I don't understand the rationale. Here are 2 examples of situations in which I do bid to make it 'even'.
(a) An infexible hand. Holding a hand without Jesters or Wizards and a lot of mid-range cards which may or may not win a trick I am likely to be set.
Consequently I bid even and am happy if I can escape the hand without losing any points.
(b) If making an even bid gives me a major point gain I bid even. (Depending on the score and the stage of the game.)
For example in a 3-handed game with the first 2 players bidding 1 when 10 tricks are available I am happy to bid 8 so that we all make our bids. My point gain is significant. (Of course good opponents will set themselves in order to stop such a ploy.)
* Another reason to make an even bid is to maintain the status quo when enjoying a significant lead. That is the reason for the "Canadian Rule".
* If you are a really good player and have the right cards it is good strategy to bid to make it even but with the intention of making your own bid and setting others.