For the most part yeah, the owner is the biggest issue for the team. I sure haven't seen a situation where the fans of a team actually take up advertising space showing their discontent with the owner/leadership team. The fans have a memory, and the shadow of what happened to Alfie hangs over every current decision- exposing Methot, trading Karlsson, the horrible trade involving Hoffman, and with this trading a first pick for Duchene and then trading him for picks right after he starts being a core part of the team. So yeah, crowds are down, as a percentage of capacity Ottawa are second last (well as of midway through the season, that's the last reliable stat I have) which is amazing considering it's, well, Ottawa.
There are a bunch of other issues- yeah the stadium is in a poor position but it's not as bad as people say and parking is relatively cheap (as low as $15). Of course having the downtown arena would be much better, however Melnyk's intransigence could be more due to a lack of money on his end than anything else. He's- to paraphrase an article I read- 'Billionaire poor' in that while he certainly has a lot of money, it's quite possible he isn't at the level of wealth to be able to pay for a stadium. Teams are owned by consortiums to protect against the sort of vulnerability that happen with a single owner.
And of course form is another reason for people not turning up. If you give people the impression you're icing an AHL team in the NHL, well, why would people turn up? Why would people buy jumpers with their favourite player on the back when the owner trades everyone's favourite player near the end of every season? The number of Duchene jumpers I see during broadcast is really high. Will those people be buying another Senators jersey anytime soon? Hmm.
However. That all said, I can't imagine the team being moved. NHL management seems to prefer expansion over shifting teams nowadays and really, taking another team away from Canada (I honestly don't see them being moved to Quebec, which is a smaller market than Ottawa) just seems like a terrible idea.
The Senators podcast I listen to has this season decided to intro their episodes with this section of this song, and honestly... Yeah, it's pretty apt