I'm just going to ignore the strawman argument.
Let's start off by where we agree: have 27-23-73 been anywhere near good enough? No, not even close: in 19:09 of 5v5 TOI across two games, they're 45% CF% and a team-worst 30% xGF%; and have only generated one more HDCF than the Lowry line (3 vs 2). This is even more disappointing, considering they are given the majority of the minutes against COL's checking line of Wood-Colton-Kiviranta.
Now the question becomes: why? And I think as this thread has evolved, people have slowly begun to hover around the same point - some are a little more fiery than others, but the focus has been on Ehlers for his "big mistakes". But as some have pointed out, and I would agree with - he's the only one on that line with the puck to make mistakes with as WPG tries to get from their DZ and through the NZ! Not saying he had a perfect game and it was the 4 other players (and 1 other goaltender) that were worse than him at all times, but no wonder he's so divisive.
Garret has been tracking the microstats, and although I don't currently have the means to subscribe, he's at least posted a few things publically: this look at defencemen's attempts at exits (and entries) lays things out for me, IMO:
There's two things: first, any defencemen not named Morrissey are constantly chipping out the puck from the DZ 70%+ of the time (reverse of controlled exit %). Can't shoot the puck on net in the OZ if you are constantly giving the puck back to your opponent to "relieve pressure" in the DZ. Second: only Morrissey, Dillon, and DeMelo-ish have been "clean" in their exit attempts (be that chip outs or whatnot). Stanley looks "cleaner" than Samberg but that because 54 is the attempting to maintain possession, while 64 is just chipping it out (if he's not hitting his opponent).
Let's connect the dots. 27-23-73 are struggling for offence. Ehlers is carrying the load. They don't often start with the puck from their own DZ, nor do they get the opportunities to start with the puck in the OZF. And then we come to the crux - okay, something needs to change, if only the 44-2 pairing are treading water
while every other line has been struggling (if Georgiev isn't letting in every second shot attempt).
All the while: the top line has at least scored some nice goals, but they've been gashed by COL's respective top 6 (especially when paired up with Pionk against them) - so your goaltender whose preferred style of play is to be "big-and-boring" has been facing 1.3 shots every minute of each game thus far, which drops to just under 1 if it's only unblocked shots. This is all with Bowness
preferred hard matchups. None of that is simply good at all. You need to change it up.
So what do you change it to? Well again: neither Scheifele nor the coaching staff apparently trusts Ehlers on the top line, so 27-55-13 probably isn't an option. Maybe getting Schmidt in for Stanley could help some, if not just for on-ice results then at least for the vibes and communication on the ice (because there were certainly a lot of communication breakdowns to end that 2nd period, giving up three straight goals) - but you still have your best (and only) puck mover in Morrissey taking the heavy minutes with the Lowry line, as 5-4 continue to stink with any line. Oh, and that Lowry line is "unchangeable" too - that matchup line "only works" if 62 and 22 are with him, apparently. Perfetti has proven he's a top 12 player on this team, yet the coaching staff only likes him in top 6 roles (which feels very contradictory). We haven't even gotten to "unlocking" the whole point of acquiring Toffoli's ability to score (because again, the Jets are struggling to even have the puck on their sticks in dangerous areas to begin with).
These are all problems we've seen since January. This was always the risk, and the gamble that this coaching staff has made, and made very intentionally to end the year too when everyone was feeling good about the vibes on a nice little winning streak but just average underlying numbers: that if they could instill a lot of defensive structure, that the high-end talent of their top players would outscore and/or outsave all the other issues. When one or neither happens, these two games vs COL are what you get. And now the Jets might not realistically have a known answer to address them.