It depends what question you’re trying to answer here.
Is the AFC East weak compared to other divisions? (Pretty self-explanatory - overall division record.)
Do the Patriots benefit playing in the AFC East? (Their winning pct vs. the AFC East is lower than vs. the rest of the NFL, so probably not. Miami’s success against New England does make that equation pretty strange though.)
Is Buff/Mia/NYJ the worst combined record of any divisional 3-team combo in the league? (Yes.)
Is the Buffalo/Mia/NYJ record caused by their own ineptitude only or by having to play the Patriots too? Are they really the worst group of 3 teams in any division in the NFL in a vacuum, or is this caused by playing the Patriots frequently? (When you have a team winning .750+ of their games, that could potentially be the x-factor in that statistic. You’d subtract the Patriots games from Mia/Buff/NYJ records...since that does factor into the record of the bottom 3 teams. You have to isolate the teams minus the Patriots impact to answer this question...bottom 3 teams in other divisions are facing a weaker #1, aka a more beatable “tougher opponent” than the Patriots.)
Has the AFC East failed to produce a real SB contender to challenge the Pats since 2001? (Heck yes. Cumulative winning pct be damned...what a catastrophic failure...over SIXTY combined seasons they have not even produced a single 12-game winner. I think the sell-out, cap stretching Jets of 2010-11 with Sanchez was the only one with two straight winning seasons. What a sht show.)