Sadly, from my limited understanding, due to the engine location change on the airframe, the plane naturally pitches up... making it necessary.
One thing seems clear to the external observer, this is a 737 in name only.
Most jet airliners have a pitch up tendency. The problem with the MAX is two related issues...
First, FAA has a requirement that stick pressure must follow certain patterns - namely, the harder you pull/push the stick, the more the plane reacts. Due to engine placement, the MAX did not meet this requirement.
Second, Boeing needed to create the MAX with minimal (approaching zero) re-training of pilots.
MCAS was supposed to meet both needs - by having MCAS adjust the stabilizer, the stick behavior/feel came back within requirements. And because it was all automatic, the pilots didn't need retraining in the simulator. Correcting the stick feel without a system like MCAS would have required more substantial changes to the plane, which would have likely required simulator time, which was likely a deal-breaker for some airlines.
The 737 has a feature almost no other new plane have: you can order it with a internal staircase so people can leave the plane without a specialized airport terminal.
This feature requires the plane to keep its current overall shape, otherwise the staircase thingy would not work.
So to keep this feature, while putting a bigger engine on the plane, they had to move the engine forward, and change its shape too, otherwise the engine wouldn't fit between the wing and the ground.
Then THAT caused the necessity of MCAS.
So long story short: wanting to keep backward compatiblity with the 737 staircase, led to the engine hack, that then to maintain backward compatiblity with the handling led to the MCAS hack...
So, it IS a 737, in the sense they kept the staircase and to do that ended needing the MCAS...
The other option would have been abandon the staircase entirely and make a taller plane, this would allow a bigger engine with no handling changes, but although this would remain a 737 from handling perspective, it would not be a 737 from the airports perspective: it would need to remodel the airports to install bridges or purchase of ladder trucks.
No that would not be the major problem. Specifically since practically any airport nowadays has the infrastructure to service such a plane. This was quite different 50 years ago.
The reason why they couldn't have heightened it was that a new type certification would have been required and Boeing wanted to avoid exactly that at all cost.
Even at the cost of 346 dead people.
I assumed the stairs were not longer installed, and the height of the 737 was just an anachronism.
Video for those that haven't seen them:
They also probably could have succeeded, too, if not for other systemic problems within the company.
You say Boeing had no choice, but one choice was to acknowledge the problems, aim to keep the type certification with additional training, and negotiate with its potential customers on that basis. There is no law of mankind or nature that says Boeing is entitled to a certain number of sales at a particular profit.