There’s a lot of aspects to this game that with minor tweaking would take out the stress and hours upon hours of mind numbing grinding and camping. Aspects that wouldn’t take months to implement into the game, but would greatly enhance gameplay making it more enjoyable.
You bring up a lot of good points, and I agree with many of them. There are a few that I'd like to play devils advocate on though
For the updates a few times a year
OTM seems to have been releasing updates quarterly (every 3 months). They may not have been the largest updates, for instance one of them was just cooking, another was just an auction house. The way the game is built, and the way Apple approves their updates isn't conducive to the way the game is built to have an update every week, or even month. The update has to be planned out, then built, then it has to go through bug checking QA, bug fixes, then testing (on all the many types of devices Android and Apple), then it goes back for more fixes, testing, fixes, and so on. After there's a product it gets released to beta test, players start tearing it apart finding bugs, and the bugs get fixed. Then it gets shipped to Apple/Google to get put in the app/play store, and Apple needs to approve it first. Then we get the update. It's a long process, which takes a lot of people coordinating efforts, and a small game company doesn't have the resources to do all that every month. Which is why we get quarterly updates.
As for the content of the updates, the last few ones we got cross-platform play, cooking, another was just an auction house, earlier than that were battle mounts, and fishing. They don't sound like much on their own, but it took effort to create those and get them into the game. They aren't as flashy as a new zone, but they were necessary to have, and people were asking for them since the beginning of the game back in 2011. Now I know that they should have been done a long time ago, and probably a larger game company could have done all of this earlier along with events. When Celtic Heroes was released, it was a good mobile MMO, and part of that was lack of competition in the mobile MMO category. That time has come to an end since there are a lot of other competing games now. And CH some features haven't kept up with the competition. This is one reason, in my mind, why OTM has tried to get CH up to speed with new features, and have been learning how to monetize their game better so that they can keep up with the competition. I saw someone say recently about Pokemon Go, which was released 1.5 years ago, that if you give it a few months it will finally be ready for it's initial release. That's kind of how I feel about CH right now with regards to its competitors. If this game was released right now instead of back in 2011, it would still be lacking many of the features that its competitors have.
tl;dr: We don't get updates as often because OTM is a small company. OTM is adding critical features now, but CH is not keeping up with the competition.