As pool is using PPLNS system for payouts, the 17xxx ports will only switch to the most profitable when a block is found on the currently mined one. This is to prevent users losing their shares submitted (losing credits due to early switching) and it is considered to be a smarter and better way of mining.
Maybe MPH has a plan to add coins in the future, maybe he just doesn't want to in order to save on the storage bill or keep the server loads low, who knows? We have an almost endless list of good coins waiting to be added for months, some of them are requested over 6 months ago. You can request them here but don't expect them to be added any time soon.
The pool indeed has a very limited set of coins for each algo. I guess, we either try to manage it here or find another pool or set of pools. After many years of being a vocal and loyal user of MPH, I had to realise that this pool is stalling out and despite my kind warnings to MPH, this pool does not want to keep its relevance in the game. I, for one, am switching between a few pools and this one now depending on profitability. It is not ideal, requires extra manual work but at least the payouts are much better. Sorry MPH, I am not going to lie, you will slowly lose your users. 90% of my hashrate is already somewhere else in average.
I understand how you felt and your disappointment.
I am personally having very busy days including the pool backend works. As I already mentioned before, I'm running more than +40 servers. Has increased few more so I think it's nearly 50 now.
There's some other pools out there that only runs one or two coins.
You would think that why they don't add more coins, but it's quite difficult to maintain several coins because it needs additional maintenance and db tweak, wallet updates.
I also agree that my work progress is slow these days.
I'm actually developer and not server operator but I'm currently under heavy job monitoring several servers and repairing every day.
For example here's the list of jobs I did recently.
1. bittrex have reset pool account verification level and it stopped whole auto exchange process.
2. Zcoin wallet breaks mining due to its latest malicious transaction bug
3. Dash mandatory update.
4. Monero wallet stopped syncing time to time without reason.
5. Expanse will hardfork soon. Block reward changes.
6. Internal Aurora DB performance decreased lately from AWS update. Had to tweak some logic and test to flush old share data.
7. Bitcoin gold snapshot
8. Asia server went down few days ago resulting 3 servers offline due to datacenter issue.
9. Moving, adding monero/zcoin servers at singapore region
10. Launch new server from digitalocean with bigger space.
11. Bitcoin gold syncing
12. Answering questions and OTP reset requests. I receive nearly +30 questions daily.
Trust me, I work day and night everyday including weekends.
I hope my new hired men do their job quickly.
Sorry for inconvenience.
I have never implied you were not busy and I always appreciated the fact there are so many things to be done on the backend side (we've had these conversations before, and all kudos to you for your hard work). What causes frustration to many of us is that we were promised many coins to be added a long time ago and these are still not delivered. According to another statement, Zen should be already up and running.
As I mentioned in a previous post, I feel there will ALWAYS be something critically important to do with the backend and maintaining current wallets (even just keeping up-to-date with their status and news is difficult, I know) but due to that, coin additions will be just delayed forever. And when I am looking at from your angle, it is completely understandable you don't want throw more oil on the fire by adding a new coin.
And then Auroracoin was added that was not asked by anyone on this forum and currently mined by 7 miners. I understand it was easy and quick to set up but that does not make us feel better about it.
There should be at least a date (or a smaller time window) set that users can hold onto when expecting new coins. The word "soon" loses its meaningfulness when applied for time frames such as months in a fast-paced crypto world. You really should just say no to people when new coins are requested so you don't keep their hopes up or prioritise and actually add them within a couple of weeks if promised. And failing at this is causing the real frustration.
EDIT: My suggestion is to publish your plan of coin additions which should at least contain the list of coins and an actual date or timeframe they will be added (comments are also appreciated). Then users will know what to expect from MPH and you also have something you can work towards to.