I think bombardier choices were bankrupt or this.

 One one hand not only do you lose out the taxpayer investment but you lose out on payroll and income taxes generated by keeping these workers employed (assuming they pay no corporate tax due to tax credits), their tiered suppliers and no unemployment payouts. 

But by getting Airbus involved they get around the tariffs so American companies are more likely to buy them, but Bombardier will probably receive more orders than they would ever get on their own due to Airbus's stability, marketing and sales, and confidence in one of the most efficient, comfortable and designed commercial plane ever made. Airlines want to buy them (I believe) but why would they if Bombardier went bankrupt. Personally I hate all subsidies but Boeing "The King of Subsidies" just got checkmated and I love it. Hopefully they will use this chance to develop their other business interests to maybe build streetcars on time for example.