Then the JetBlue and Soutuwest program wouldn't be a good choice.
Here is a comparison and by no means is the end all. So think of it this way and make Delta a hypothetical goal.
Let's compare ATP and JetBlue Gateway Select. Add in training time and turbine PIC time to be competitive for a DAL position.
Through ATP flight school, in a perfect world it would only take you 6 or more years to train, build time, have a regional cover your ATP cert, build time again and senority for regional FO experience, upgrade to CA and have PIC jet time to have your app in at Delta.
Gateway select will have you at JetBlue in 3 1/2yrs but you will have no PIC turbine time since you bypassed regional experience. So add in 4 years to gain senority and upgrade to CA. Then 2 years to build PIC time. Plus even if you wanted to make a lateral transition to another company like Spirit or Southwest instead of Delta, you are stuck at JetBlue without that TPIC time.
So unless you absolutely LOVE jetblue and want a career at JetBlue it wouldn't be a good choice to use it as a stepping stone. They also don't tell you that you pay for your own ATP cert, which is why tuition is more. Yes, you get a huge early bump in pay but you can make that up on the back end if you went to a flight school with more options like ATP.
3 steps forward and 2 steps back.