There never was a limit previously -- that was the the whole problem.
When the game first came out Crafting on the Cheap was the only option -- so 50% (max CoC) was "max".
Then alliance wars came out first with a 20% and then a 25% crafting boost -- so when combined with a 50% CoC, 70% and 75% became the new "max" respectively.
Then the 2013 Halloween boxes came out with a 20% Headless Handyman crafting bonus -- so 95% became the new "max"
Finally the Premium boxes came out with a 20% crafting bonus themselves -- so 100% became "max"
If the boosts and boxes had existed back when 50% CoC was the only option -- 100% would have been the "max" then too.
Back when 50% was the only option a unique level 21 M24 was considered the top longrifle. Using 50% Crafting on the Cheap it cost players 500 fuel to upgrade from level 20 to level 21. It happened all the time -- and players considered it a bargain.
Now that Con has finally put in a limit of 80% it costs 490 fuel to upgrade a unique 107 from 49 to 50 when you stack boosts to reach the cap. That's nearly the same as when the M-24 was king -- so in terms or cost we're back to where people used to consider it bargain to upgrade their top level weapons and gear.
Since we're back to that point, I don't see it changing anytime soon.
If Con has put in a limit in at the very start we wouldn't be having this discussion at all. But he has a very bad habit of forgetting limits.
If at some point new higher level (60+) level weapons and gear come out, I can see Con raising the crafting cap, but note that would take an increase in level of about 50 (i.e. level 100 weapons) to warrant an increase of 10% in the crafting bonus while preserving a target of about 500 fuel for a top-level weapons/gears.