The MRJ90 and E175-E2 are done
 

Easy solution: operate them on a mainline certificate.

Or lease them out foreign carriers.

We may be forgetting the success that jetBlue had with the E-190 when few others were flying it. It is possible for the same thing to occur with one of the LCC's or ULCC's. It is also possible for these aircraft to be utilized in other locales by non-US carriers, or in a start up endeavor. I don't think the aircraft are done.

I've been saying for years that foreign airframers who gloss over scope limits when designing large RJs are making a big mistake.

It's no longer a simple matter of making a trip through the BK drive-through to eliminate annoying labor contract provisions.

And it's tough for mainline to make money directly operating RJ's close to 100 seats. At the 100 seat point, you have to pay another FA, and that puts the economics in a whole. This is why narrow-bodies's keep getting bigger of the years, to get further away from that 80-149 seat economic trough.

Outsourced flying is the only way to make a lot of RJ routes economical.

Little problem...the vast majority of the market for RJ's is in the US, the land of the big scope clause.

The problem is it takes hundreds, or many hundreds of production aircraft just to break even on the R&D cost of developing a new aircraft.

If you cut out most of the US market, and turn what you thought was a 1000 airplane production run into a 300 airplane run, you're not going to make any money. You'll be lucky to break even.

For example, the A380 with about 300 orders is billions of dollars in the hole and will never even begin to recover it's costs.

Time to break out the Q400 and ATR 600 orders! LOL

Aircraft design/manufacture is a decades long process. Pilot contracts are short term instruments, and given the history of pilots selling their souls for a few dollars, those airplanes will fly where ever the companies that buy them, want them. Never underestimate greed.

Yet at the moment the manufactures needed that cave it did not happen.