I don't want to get in a fight with the NXT people, but it's conjecture to assume that the NXT creators would have allowed more than a total investment of 21 BTC. The NXT IPO was halted suddenly 6 weeks before the posted end date and well below the desired number of stakeholders. In my opinion, there's no reason to believe it wouldn't have ended much sooner if there was more interest earlier. For example, if the NXT IPO received 21BTC on the first day why do we think it wouldn't have been shut down immediately?
We can only speculate on this if would be ended the 1st day or not?
Was the 21 btc the limit to invest?
If the dev wanted to have greater number of stakeholders within 21 BTC
they should have been set a smaller btc cap per person "investor".
Was it ended sooner for other reasons unknown to us or because 21 btc was collected?
Who knows the answers to this questions?!
It ended how it ended we can not change it any more
so there is no reason to dissipate any more energy and time to this issue.