Ultimately that's all you need to look at. Sure, Wenger has flaws but so will the next guy. Quite possibly more serious ones given how some of the people mooted as possible replacements have got on in the last couple of seasons. For all his flaws he's won us a couple of trophies in the last 2 years, IMO that buys him some time and he deserves a chance to push on for the biggest prizes.
I do think Saturday's result is important because despite their start I expect Chelsea to be 'up there' come May. In all the seasons I've seen us win the title we've got good results away at our rivals.