So you'd rather them not? See, what the problem is, you can't satisfy everyone. If they released fewer versions, people would cry that the versions aren't frequent enought. If they release often, people cry that they release to many.
You can't satisfy everyone, so they do what is best for the business and the general population of users. Frankly, most of their customer base does not modify their board, so upgrades are as simple as uploading the files. For people that modify their board, the price of modifications is the stepped up difficutlty in upgrading.
Believe me, it's far better that IP releases upgrades as soon as bugs or security holes are fix. Want the opposite extreme? Look at MSA's wwwboard. that thing hasn't been upgrades since 1996 or 1997 (save for the one line of code he changed new years eve 2k to prevent the 19100 bug). It's far known that that's the most buggy, insecure piece of software out there....but he refuses to work on it.
Aren't you happier knowing that the software you run is activly supported and fixed as soon as something is discovered?
Another one oft heard: "Why don't they just wait until there are no bugs before releasing a version?"
1) No such thing as bug free software
2) Again, people would complain it's taking too long. People already complained that about the 6.x series.
2 cents
