Because we might still not draft a first-round DT, or worse, draft one that performs like Mazi has up to this point. Odighizuwa is a very solid rotation player, and that costs more than you'd think, but paying him should not be used as an excuse to not try to get better.
I prefer that we transition tag him this year since we do not have a qualified replacement in hand. That will cost us ... around $19 million, but it gives us a chance to actually draft a player(s) to try to usurp him and make it unnecessary to give him a costly long-term deal. The difference in the transition tag and franchise tag at DT is about $4 million, I believe, but I think the transition tag will be enough to retain him or at least learn his market value before deciding whether to match any long-term deal.