We regularly dispatch without alternate, with an estimated fuel on arrival with as little as 1,6 T (for a 737-600 or 700). As long as you understand the consequences I find it acceptable. E.g. what if you have an engine failure, stuck flap or anti-skid fault. If you always leave yourself a way out, it's just a numbers game. Declare a mayday, skip the long complicated checklist, do what it takes to get yourself on the ground with the fuel you've got onboard. Rather 1.6 T on arrival to an airport with 3 long dry runways than X.X on arrival to a slippery short runway with alternate another slippery short runway. In either case if you've got an anti-skid fault you've sold yourself short.