[bill_mon]

Because most devices can't be updated? Supporting version 4+ gives you a much larger audience than limiting to version 7+.

[MrDresden]

I think this was a very logical thing for them to do.

Supporting platforms that old comes with a massive amount of headaches. It is hard enough for big teams of applications with high MRR to do, and is near impossible for a FOSS application to do in perpetuity.