Well I can tell you he's had 1000-1200 Patrons for the last 6 years. The total goes up and down, because some people only subscribe when an update is released. It's stayed pretty steady throughout that entire period, and updates have been released every 2-3 months , apart from a few occasions when the updates have been longer, or they've had some unexpected issue to deal with, as is the case this time. So whilst it's possible you might be right with some Devs, in the case of Deepsleep, it hasn't made any difference at all.
Also Devs have to work very hard for their money. It's not a 9-5 job you know. They have to work 60-70 hours a week, and when an update is being released, it can be considerably more. And when you start your game, it's a big gamble. You have no idea whether your initial months of hard work for little reward, is going to pay off. The failure rate is extremely high and many Devs give up, because it's soul destroying to put in a ton of effort, not get any reward and then have people trashing your efforts on top of that. So if Devs get to the point, where they've achieved success and are earning a good income. Then I say good on them, because they've almost certainly had to work damn hard to get there.