The Conor not defending thing is just something haters cling to. If you actually look at how often most other champs defend or fight, it's not much different time-wise thus far. The only difference is those other fighters didn't have as many haters because they weren't as famous.
Let's look at that, numbers since conor won the FW belt and was stripped.
WSW: JJ beat Ghadelia, beat KK - 2 title fights.
WBW: Holly won BW belt a a little before conor, lost it to misha, who lost it to Nunes, who just defended it against Rousey. -4 title fights.
FLW: MM beat Cejudo, beat Elliott - 2 title fights.
BW: Cruz beat Dillashaw, defended against Urijah, and lost it to Cody. - 3 title fights.
LW: RDA beat cowboy, lost Eddie who then lost to conor.
WW: Lawler defended against Condit, Lost to Woodley, who fought to a draw against WB, and has rematch scheduled. - 3 title fights.
MW:Bisping beat Rockhold, defended against Hendo - 2 title fights.
LHW: DC injured, Jones wins interim, jones popped, DC beat Anderson, got injured again. - 1
HW: Stipe beats Werdum, defended against Overreem - 2 title fights.
So every division had at least 1 title fight, most 2 title fights, many had 3 title fights. Notice which division is missing?