It's possible to write a lot about gamma 2.2, and that it's the only one correct. But not everyone works by-design and it's incorrect to fit everyone in one size.
I don't work in 2.2 (and ecximer also doesn't), but now I have to change my workflow. For example, the latest gif I posted above is made in gamma 1.4, and I can't achieve the same result in latest builds. That leads to the need of post-processing and excessove manipulations... what for??
It's much simpler to leave the switch in settings, and don't make life harder for users. That would be their choice in which gamma to work.
But please don't tell me that it's only correct to work in 2.2 - there are many opinions about this.
The problem is that gamma is just not an artistic control tool - it HAS to be used in some way, otherwise your workflow will be ruined. Yes, jpegs have to have 2.2. Yes, you can use 1.6 to get more contrast. But this is deliberately lying in the image format. It will eventually cause troubles.
Example1: HDRs vs LDRs. Say you apply gamma 1.6. Then one day you want to save an EXR. EXRs are without gamma - so do you leave gamma to 1.0? That would erase your gamma postpro effect. So actually you would need to apply some gamma <1.0 to get the same effect for EXRs as applying gamma <2.2 for JPEGs. This gets ugly quickly.
Example 2: Misinformed/outdated tutorials on the internet claim "mac has gamma 1.8", or "LCD monitors have gamma 2.4". While that may be true (in some totally irrelevant sense), it may fool people into thinking they should change gamma in every scene to make it "more correct", while in the reality, the way 3dsmax is implemented, ONLY 2.2 is correct (because it specifies the gamma of the output color space, not any hardware - OS handles that for you).
This is using tools outside its intended purpose, as hacks. It caused some bugs in Corona with 3dsmax, with different frame buffers and render elements, so I have taken it out. Plus to control gamma, I had to actually first remove the 3dsmax gamma, then apply Corona gamma, resulting in longer save times.
Now, I am not saying some gamma-like control could not be added - but it should not be named gamma, but rather something like "midtone balance", with default 1.0, applied both to HDR and LDR indiscriminatively.
I first encountered this gamma stuff when doing this image:
I was trying to match my real world compter. But for some unknown reason, I was unable to get any light inside of the case - either it was too dark, or everything else was overbright. I tried different tricks, invisible lights, removing glass, increasing GI amount > 1.0 (
gotta love vray ;)), but nothing looked remotely right. Then I discovered the linear workflow tutorial, set it up, and BAM, everything was exactly like in reality. Of course, I thought, everything around was too washed up, unrealistic, etc. I wanted to go back to 1.0, but I had to stick with gamma 2.2 to match the reality inside the case. By the end if the project, I would never go back to 1.0 workflow.
I know I won't convince you, nobody is obliged to use only physically correct workflow - but IMHO you cannot go wrong by sticking to it, and deviating only as little as possible ;).