I enjoy the little niche here, with DF as it is, and probably what it will be.
Going big implies all sorts of things. Other than Toady's(and Threetoe's) "Life's work" as mentioned above. Going big and commercial means accelerating the production, and bringing the certain low tide of players' and/or investors' attention to come sooner, which is harder to get through, than what it is now: updating moderately slowly but steadily. Just as you are tired of playing the current version, the hope of upcoming major updates arises.
And for a great game DF is, commercialising is almost sure to bring prominent sum of new(er) players to it, whose passion for a game would dull over time, as we always do =)
That with the forthcoming emergence of future games in the same category, as what has been seen late days, e.g. Gnomoria, A Game of Dwarves and possibly Castle Story, The Dig-build-drink-fight-n'-lose-for-fun type of games. That means at certain point, a vaccum of new player would come for DF, and as most commercial game would come to a silent death, I suspect that would be true to DF if it commercialise, and such death might very well come much earlier than what would be a 1.0 finale down the current course.
And speaking of the crowdfunding thing, the projects' failing rate is simply too high. As much as a half on Kickstarter.
All in all, I wish Toady good health and don't change mind. So DF would be a game to play for my lifetime.